Form N-Q

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, DC 20549

FORM N-Q


QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED MANAGEMENT INVESTMENT COMPANY

Investment Company Act file number         811-6623         

        Nuveen California Select Tax-Free Income Portfolio         
(Exact name of registrant as specified in charter)

Nuveen Investments
        333 West Wacker Drive, Chicago, Illinois 60606         
(Address of principal executive offices) (Zip code)


Kevin J. McCarthy Vice President and Secretary
        333 West Wacker Drive, Chicago, Illinois 60606         
(Name and address of agent for service)

Registrant's telephone number, including area code:         312-917-7700        

Date of fiscal year end:            3/31          

Date of reporting period:         6/30/09         

Form N-Q is to be used by management investment companies, other than small business investment companies registered on Form N-5 (§§ 239.24 and 274.5 of this chapter), to file reports with the Commission, not later than 60 days after the close of the first and third fiscal quarters, pursuant to rule 30b1-5 under the Investment Company Act of 1940 (17 CFR 270.30b1-5). The Commission may use the information provided on Form N-Q in its regulatory, disclosure review, inspection, and policymaking roles.

A registrant is required to disclose the information specified by Form N-Q, and the Commission will make this information public. A registrant is not required to respond to the collection of information contained in Form N-Q unless the Form displays a currently valid Office of Management and Budget ("OMB") control number. Please direct comments concerning the accuracy of the information collection burden estimate and any suggestions for reducing the burden to the Secretary, Securities and Exchange Commission, 450 Fifth Street, NW, Washington, DC 20549-0609. The OMB has reviewed this collection of information under the clearance requirements of 44 U.S.C. § 3507.

Item 1. Schedule of Investments

    Portfolio of Investments (Unaudited)             
    Nuveen California Select Tax-Free Income Portfolio (NXC)             
    June 30, 2009             
Principal        Optional Call         
Amount (000)    Description (1)    Provisions (2)    Ratings (3)    Value 
    Consumer Staples – 3.5%             
$        170    California County Tobacco Securitization Agency, Tobacco Settlement Asset-Backed Bonds, Sonoma    6/15 at 100.00    BBB   $   151,402 
     County Tobacco Securitization Corporation, Series 2005, 4.250%, 6/01/21             
1,170    California County Tobacco Securitization Agency, Tobacco Settlement Asset-Backed Revenue    6/12 at 100.00    BBB    1,095,073 
     Bonds, Fresno County Tobacco Funding Corporation, Series 2002, 5.625%, 6/01/23             
4,045    Golden State Tobacco Securitization Corporation, California, Enhanced Tobacco Settlement    6/22 at 100.00    BBB    1,700,518 
     Asset-Backed Bonds, Series 2007A-2, 0.000%, 6/01/37             
5,385    Total Consumer Staples            2,946,993 
    Education and Civic Organizations – 9.6%             
3,000    California Educational Facilities Authority, Revenue Bonds, Santa Clara University, Series    4/18 at 100.00    Aa3    3,073,650 
     2008A, 5.625%, 4/01/37             
45    California Educational Facilities Authority, Revenue Bonds, University of Redlands, Series    10/15 at 100.00    A3    39,299 
     2005A, 5.000%, 10/01/35             
1,000    California Educational Facilities Authority, Revenue Bonds, University of San Diego, Series    10/12 at 100.00    A2    979,360 
     2002A, 5.500%, 10/01/32             
    California Educational Facilities Authority, Revenue Bonds, University of the Pacific,             
    Series 2006:             
35     5.000%, 11/01/21    11/15 at 100.00    A2    34,148 
45     5.000%, 11/01/25    11/15 at 100.00    A2    41,587 
3,000    California Infrastructure Economic Development Bank, Revenue Bonds, J. David Gladstone    10/11 at 101.00    A–    3,067,740 
     Institutes, Series 2001, 5.500%, 10/01/19             
1,000    Long Beach Bond Financing Authority, California, Lease Revenue Refunding Bonds, Long Beach    11/11 at 101.00    BBB    842,520 
     Aquarium of the South Pacific, Series 2001, 5.250%, 11/01/30 – AMBAC Insured             
8,125    Total Education and Civic Organizations            8,078,304 
    Health Care – 12.2%             
110    California Health Facilities Financing Authority, Revenue Bonds, Kaiser Permanante System,    4/16 at 100.00    A+    95,744 
     Series 2006, 5.000%, 4/01/37             
2,550    California Health Facilities Financing Authority, Revenue Bonds, Sutter Health, Series 2007A,    11/16 at 100.00    Aa3    2,286,993 
     5.250%, 11/15/46 (UB)             
2,000    California Infrastructure Economic Development Bank, Revenue Bonds, Kaiser Hospital Assistance    8/11 at 102.00    A+    1,955,100 
     LLC, Series 2001A, 5.550%, 8/01/31             
1,500    California Statewide Community Development Authority, Hospital Revenue Bonds, Monterey    6/13 at 100.00    AAA    1,580,370 
     Peninsula Hospital, Series 2003B, 5.250%, 6/01/18 – FSA Insured             
1,500    California Statewide Community Development Authority, Insured Mortgage Hospital Revenue Bonds,    11/09 at 102.00    A    1,401,225 
     Mission Community Hospital, Series 2001, 5.375%, 11/01/26             
545    California Statewide Community Development Authority, Revenue Bonds, Kaiser Permanente System,    8/16 at 100.00    A+    504,714 
     Series 2001C, 5.250%, 8/01/31             
1,880    California Statewide Community Development Authority, Revenue Bonds, Los Angeles Orthopaedic    12/09 at 100.00    BBB+    1,874,416 
     Hospital Foundation, Series 2000, 5.500%, 6/01/17 – AMBAC Insured             
540    Loma Linda, California, Hospital Revenue Bonds, Loma Linda University Medical Center, Series    12/18 at 100.00    BBB    568,447 
     2008A, 8.250%, 12/01/38             
10,625    Total Health Care            10,267,009 
    Housing/Multifamily – 0.8%             
750    California Statewide Community Development Authority, Student Housing Revenue Bonds, EAH –    8/12 at 100.00    Baa1    684,525 
     Irvine East Campus Apartments, LLC Project, Series 2002A, 5.500%, 8/01/22 – ACA Insured             
    Housing/Single Family – 0.1%             
115    California Housing Finance Agency, Home Mortgage Revenue Bonds, Series 2006H, 5.750%,    2/16 at 100.00    Aa2    115,024 
     8/01/30 – FGIC Insured (Alternative Minimum Tax)             
    Industrials – 1.7%             
1,015    California Pollution Control Financing Authority, Solid Waste Disposal Revenue Bonds, Republic    No Opt. Call    BBB    954,648 
     Services Inc., Series 2002C, 5.250%, 6/01/23 (Mandatory put 12/01/17) (Alternative Minimum Tax)             
500    California Pollution Control Financing Authority, Solid Waste Disposal Revenue Bonds, Waste    1/16 at 102.00    BBB    451,520 
     Management Inc., Series 2002A, 5.000%, 1/01/22 (Alternative Minimum Tax)             
1,515    Total Industrials            1,406,168 
    Long-Term Care – 2.6%             
1,500    ABAG Finance Authority for Non-Profit Corporations, California, Insured Senior Living Revenue    11/12 at 100.00    A    1,416,945 
     Bonds, Odd Fellows Home of California, Series 2003A, 5.200%, 11/15/22             
1,000    California Statewide Communities Development Authority, Revenue Bonds, Inland Regional Center    12/17 at 100.00    Ba1    776,810 
     Project, Series 2007, 5.250%, 12/01/27             
2,500    Total Long-Term Care            2,193,755 
    Tax Obligation/General – 21.9%             
750    California, General Obligation Bonds, Series 2004, 5.000%, 2/01/23    2/14 at 100.00    A    716,273 
1,000    Fremont Unified School District, Alameda County, California, General Obligation Bonds, Series    8/12 at 101.00    Aa3    1,018,060 
     2002A, 5.000%, 8/01/21 – FGIC Insured             
    Golden West Schools Financing Authority, California, General Obligation Revenue Refunding             
    Bonds, School District Program, Series 1999A:             
4,650     0.000%, 8/01/16 – MBIA Insured    No Opt. Call    A    3,386,270 
1,750     0.000%, 2/01/17 – MBIA Insured    No Opt. Call    A    1,222,130 
2,375     0.000%, 8/01/17 – MBIA Insured    No Opt. Call    A    1,612,815 
2,345     0.000%, 2/01/18 – MBIA Insured    No Opt. Call    A    1,511,751 
    Mountain View-Los Altos Union High School District, Santa Clara County, California, General             
    Obligation Capital Appreciation Bonds, Series 1995C:             
1,015     0.000%, 5/01/17 – MBIA Insured    No Opt. Call    Aa2    699,051 
1,080     0.000%, 5/01/18 – MBIA Insured    No Opt. Call    Aa2    685,800 
100    Roseville Joint Union High School District, Placer County, California, General Obligation    8/15 at 100.00    AA–    100,464 
     Bonds, Series 2006B, 5.000%, 8/01/27 – FGIC Insured             
3,220    Sacramento City Unified School District, Sacramento County, California, General Obligation    7/15 at 100.00    Aa3    3,229,918 
     Bonds, Series 2005, 5.000%, 7/01/27 – MBIA Insured             
1,500    San Diego Unified School District, San Diego County, California, General Obligation Bonds,    7/13 at 101.00    AAA    1,659,480 
     Series 2003E, 5.250%, 7/01/24 – FSA Insured             
2,565    Sunnyvale School District, Santa Clara County, California, General Obligation Bonds, Series    9/15 at 100.00    AAA    2,593,318 
     2005A, 5.000%, 9/01/26 – FSA Insured             
22,350    Total Tax Obligation/General            18,435,330 
    Tax Obligation/Limited – 20.3%             
1,000    Bell Community Redevelopment Agency, California, Tax Allocation Bonds, Bell Project Area,    10/13 at 100.00    BBB–    888,250 
     Series 2003, 5.625%, 10/01/33 – RAAI Insured             
3,500    California State Public Works Board, Lease Revenue Bonds, Department of Corrections,    No Opt. Call    A    4,044,772 
     Calipatria State Prison, Series 1991A, 6.500%, 9/01/17 – MBIA Insured             
1,000    California State Public Works Board, Lease Revenue Bonds, Department of Mental Health,    6/14 at 100.00    A–    963,980 
     Coalinga State Hospital, Series 2004A, 5.500%, 6/01/23             
120    Capistrano Unified School District, Orange County, California, Special Tax Bonds, Community    9/15 at 100.00    A    108,037 
     Facilities District, Series 2005, 5.000%, 9/01/24 – FGIC Insured             
360    Chino Redevelopment Agency, California, Merged Chino Redevelopment Project Area Tax Allocation    9/16 at 101.00    BBB    282,744 
     Bonds, Series 2006, 5.000%, 9/01/38 – AMBAC Insured             
1,000    Fontana Public Financing Authority, California, Tax Allocation Revenue Bonds, North Fontana    10/15 at 100.00    A    816,130 
     Redevelopment Project, Series 2005A, 5.000%, 10/01/32 – AMBAC Insured             
3,150    Golden State Tobacco Securitization Corporation, California, Tobacco Settlement Asset-Backed    6/15 at 100.00    A–    2,562,305 
     Revenue Bonds, Series 2005A, 5.000%, 6/01/45 – AMBAC Insured             
    Irvine, California, Unified School District, Community Facilities District Special Tax Bonds,             
    Series 2006A:             
60     5.000%, 9/01/26    9/16 at 100.00    N/R    52,024 
135     5.125%, 9/01/36    9/16 at 100.00    N/R    109,624 
215    Los Angeles Community Redevelopment Agency, California, Lease Revenue Bonds, Manchester Social    9/15 at 100.00    A2    189,630 
     Services Project, Series 2005, 5.000%, 9/01/37 – AMBAC Insured             
1,300    Orange County, California, Special Tax Bonds, Community Facilities District 03-1 of Ladera    8/12 at 101.00    N/R    1,139,671 
     Ranch, Series 2004A, 5.625%, 8/15/34             
105    Rialto Redevelopment Agency, California, Tax Allocation Bonds, Merged Project Area, Series    9/15 at 100.00    A–    83,859 
     2005A, 5.000%, 9/01/35 – SYNCORA GTY Insured             
130    Roseville, California, Certificates of Participation, Public Facilities, Series 2003A, 5.000%,    8/13 at 100.00    AA–    118,197 
     8/01/25 – AMBAC Insured             
605    Sacramento City Financing Authority, California, Lease Revenue Refunding Bonds, Series 1993A,    No Opt. Call    A    640,973 
     5.400%, 11/01/20 – MBIA Insured             
3,000    San Mateo County Transit District, California, Sales Tax Revenue Bonds, Series 2005A, 5.000%,    6/15 at 100.00    AA    3,110,220 
     6/01/21 – MBIA Insured             
225    San Mateo Union High School District, San Mateo County, California, Certificates of    12/17 at 100.00    N/R    199,031 
     Participation, Phase 1, Series 2007A, 5.000%, 12/15/30 – AMBAC Insured             
1,000    Santa Clara County Board of Education, California, Certificates of Participation, Series 2002,    4/12 at 101.00    A    945,660 
     5.000%, 4/01/25 – MBIA Insured             
1,000    Travis Unified School District, Solano County, California, Certificates of Participation,    9/16 at 100.00    N/R    891,680 
     Series 2006, 5.000%, 9/01/26 – FGIC Insured             
17,905    Total Tax Obligation/Limited            17,146,787 
    Transportation – 5.7%             
1,150    Foothill/Eastern Transportation Corridor Agency, California, Toll Road Revenue Bonds, Series    1/10 at 100.00    BBB–    833,946 
     1995A, 5.000%, 1/01/35             
3,500    Los Angeles Harbors Department, California, Revenue Refunding Bonds, Series 2001B, 5.500%,    8/11 at 100.00    AA    3,558,975 
     8/01/17 – AMBAC Insured (Alternative Minimum Tax)             
445    San Francisco Airports Commission, California, Revenue Bonds, San Francisco International    5/11 at 100.00    AA    382,037 
     Airport, Second Series 1999, Issue 23A, 5.000%, 5/01/30 – FGIC Insured (Alternative             
     Minimum Tax)             
5,095    Total Transportation            4,774,958 
    U.S. Guaranteed – 14.0% (4)             
400    Beverly Hills Unified School District, Los Angeles County, California, General Obligation    8/12 at 100.00    AA (4)    445,976 
     Bonds, Series 2002A, 5.000%, 8/01/26 (Pre-refunded 8/01/12)             
    California Department of Water Resources, Power Supply Revenue Bonds, Series 2002A:             
1,750     5.750%, 5/01/17 (Pre-refunded 5/01/12)    5/12 at 101.00    Aaa    1,986,723 
2,000     5.125%, 5/01/19 (Pre-refunded 5/01/12)    5/12 at 101.00    Aaa    2,235,820 
2,600    California Educational Facilities Authority, Revenue Bonds, University of the Pacific, Series    11/11 at 100.00    A2 (4)    2,854,540 
     2002, 5.250%, 11/01/21 (Pre-refunded 11/01/11)             
800    California, General Obligation Bonds, Series 2004, 5.125%, 2/01/27 (Pre-refunded 2/01/14)    2/14 at 100.00    AAA    910,752 
2,000    North Orange County Community College District, California, General Obligation Bonds, Series    8/12 at 101.00    AA (4)    2,242,020 
     2002A, 5.000%, 8/01/22 (Pre-refunded 8/01/12) – MBIA Insured             
1,000    Port of Oakland, California, Revenue Bonds, Series 2002M, 5.250%, 11/01/20 (Pre-refunded    11/12 at 100.00    A+ (4)    1,131,860 
     11/01/12) – FGIC Insured             
10,550    Total U.S. Guaranteed            11,807,691 
    Utilities – 5.5%             
645    Long Beach Bond Finance Authority, California, Natural Gas Purchase Revenue Bonds, Series    No Opt. Call    A    577,449 
     2007A, 5.500%, 11/15/37             
200    Los Angeles Department of Water and Power, California, Power System Revenue Bonds, Series    7/13 at 100.00    AA–    206,232 
     2003A-2, 5.000%, 7/01/21 – MBIA Insured             
7,600    Merced Irrigation District, California, Certificates of Participation, Water and Hydroelectric    9/16 at 64.56    A    2,859,120 
     System Projects, Series 2008A, 0.000%, 9/01/23             
215    Merced Irrigation District, California, Electric System Revenue Bonds, Series 2005, 5.125%,    9/15 at 100.00    N/R    169,919 
     9/01/31 – SYNCORA GTY Insured             
780    Turlock Irrigation District, California, Revenue Refunding Bonds, Series 1992A, 6.250%,    No Opt. Call    A1    816,293 
     1/01/12 – MBIA Insured             
9,440    Total Utilities            4,629,013 
    Water and Sewer – 2.4%             
150    Healdsburg Public Financing Authority, California, Wastewater Revenue Bonds, Series 2006,    4/16 at 100.00    AA–    137,390 
     5.000%, 4/01/36 – MBIA Insured             
250    Sacramento County Sanitation District Financing Authority, California, Revenue Bonds, Series    6/16 at 100.00    AA    247,330 
     2006, 5.000%, 12/01/31 – FGIC Insured             
825    South Feather Water and Power Agency, California, Water Revenue Certificates of Participation,    4/13 at 100.00    A    745,676 
     Solar Photovoltaic Project, Series 2003, 5.375%, 4/01/24             
1,000    Woodbridge Irrigation District, California, Certificates of Participation, Water Systems    7/13 at 100.00    A+    839,270 
     Project, Series 2003, 5.625%, 7/01/43             
2,225    Total Water and Sewer          1,969,666 
$     96,580    Total Long-Term Investments (cost $86,654,436) – 100.3%          84,455,223 
Principal               
Amount (000)    Description (1)      Ratings (3)    Value 
    Short-Term Investments – 0.8%           
$          713    State Street Bank Euro Dollar Time Deposit, 0.010%, 7/01/09      N/A  $  713,419 
    Total Short-Term Investments (cost $713,419)          713,419 
    Floating Rate Obligations – (1.8)%          (1,540,000)
    Total Investments (cost $87,367,855) – 101.1%          85,168,642 
    Other Assets Less Liabilities – 0.7%          651,183 
    Net Assets – 100%        $  84,279,825 

Fair Value Measurements

In determining the value of the Fund’s investments various inputs are used. These inputs are summarized in the three broad levels listed below:

Level 1 – Quoted prices in active markets for identical securities.

Level 2 – Other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk, etc.).

Level 3 – Significant unobservable inputs (including management’s assumptions in determining the fair value of investments).

The inputs or methodology used for valuing securities are not an indication of the risk associated with investing in those securities. The following is a summary of the Fund’s fair value measurements as of June 30, 2009:

    Level 1    Level 2    Level 3    Total 
Investments:                 
   Municipal Bonds    $        —    $84,455,223    $ —    $84,455,223 
   Short-Term Investments    713,419    —    —    713,419 
Total    $713,419    $84,455,223    $ —    $85,168,642 

Income Tax Information

The following information is presented on an income tax basis. Differences between amounts for financial statement and federal income tax purposes are primarily due to timing differences in recognizing taxable market discount, timing differences in recognizing certain gains and losses on investment transactions and the treatment of investments in inverse floating rate transactions subject to Statement of Financial Accounting Standards No. 140 (SFAS No. 140), if any. To the extent that differences arise that are permanent in nature, such amounts are reclassified within the capital accounts on the Statement of Assets and Liabilities presented in the annual report, based on their federal tax basis treatment; temporary differences do not require reclassification. Temporary and permanent differences do not impact the net asset values of the Fund.

At June 30, 2009, the cost of investments was $85,820,299.

Gross unrealized appreciation and gross unrealized depreciation of investments at June 30, 2009, were as follows:

Gross unrealized:     
  Appreciation    $ 2,677,961 
  Depreciation    (4,873,262)
Net unrealized appreciation (depreciation) of investments    $(2,195,301)

(1)    All percentages shown in the Portfolio of Investments are based on net assets. 
(2)    Optional Call Provisions: Dates (month and year) and prices of the earliest optional call or redemption. 
    There may be other call provisions at varying prices at later dates. Certain mortgage-backed securities 
    may be subject to periodic principal paydowns. 
(3)    Ratings: Using the higher of Standard & Poor’s Group (“Standard & Poor’s”) or Moody’s Investor Service, 
    Inc. (“Moody’s”) rating. Ratings below BBB by Standard & Poor’s or Baa by Moody’s are considered to be 
    below investment grade. 
(4)    Backed by an escrow or trust containing sufficient U.S. Government or U.S. Government agency securities 
    which ensure the timely payment of principal and interest. Such investments are normally considered to 
    be equivalent to AAA rated securities. 
N/A    Not applicable. 
N/R    Not rated. 
(UB)    Underlying bond of an inverse floating rate trust reflected as a financing transaction pursuant to the 
    provisions of SFAS No. 140. 

Item 2. Controls and Procedures.

  1. The registrant's principal executive and principal financial officers, or persons performing similar functions, have concluded that the registrant's disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940, as amended (the "1940 Act") (17 CFR 270.30a-3(c))) are effective, as of a date within 90 days of the filing date of this report that includes the disclosure required by this paragraph, based on their evaluation of the controls and procedures required by Rule 30a-3(b) under the 1940 Act (17 CFR 270.30a-3(b)) and Rule 13a-15(b) or 15d-15(b) under the Securities Exchange Act of 1934 (17 CFR 240.13a-15(b) or 240.15d-15(b)).
  2. There were no changes in the registrant's internal control over financial reporting (as defined in Rule 30a-3(d) under the 1940 Act (17 CFR 270.30a-3(d)) that occurred during the registrant's last fiscal quarter that have materially affected, or are reasonably likely to materially affect, the registrant's internal control over financial reporting.

Item 3. Exhibits.

File as exhibits as part of this Form a separate certification for each principal executive officer and principal financial officer of the registrant as required by Rule 30a-2(a) under the 1940 Act (17 CFR 270.30a-2(a)), exactly as set forth below: See EX-99 CERT attached hereto.


SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

(Registrant)         Nuveen California Select Tax-Free Income Portfolio         

By (Signature and Title)          /s/ Kevin J. McCarthy                    
                                                  Kevin J. McCarthy
                                                  Vice President and Secretary

Date         August 28, 2009        

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By (Signature and Title)         /s/ Gifford R. Zimmerman                    
                                                 Gifford R. Zimmerman
                                                 Chief Administrative Officer (principal executive officer) 

Date         August 28, 2009        

By (Signature and Title)         /s/ Stephen D. Foy                              
                                                 Stephen D. Foy
                                                 Vice President and Controller (principal financial officer) 

Date        August 28, 2009