UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                                  SCHEDULE 13G

                    UNDER THE SECURITIES EXCHANGE ACT OF 1934

                                AMENDMENT NO. 1*

                         ITT EDUCATIONAL SERVICES, INC.
                                (Name of Issuer)

                                  COMMON STOCK
                         (Title of Class of Securities)

                                    45068B109
                                 (CUSIP Number)

                                 MARCH 31, 2001
             (Date of Event Which Requires Filing of this Statement)


CHECK THE APPROPRIATE BOX TO DESIGNATE THE RULE PURSUANT TO WHICH THIS
SCHEDULE IS FILED:

                              [X] RULE 13d-1(b)
                              [ ] RULE 13d-1(c)
                              [ ] RULE 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).





CUSIP No. 45068B109                 13G

1.       NAME OF REPORTING PERSON (S.S. or I.R.S. Identification No. of Above
         Person)

         Waddell & Reed Investment Management Company  Tax ID No. 48-1106973

2.       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP:

         (a)      [ ]
         (b)      [ ]

3.       SEC USE ONLY

4.       CITIZENSHIP OR PLACE OF ORGANIZATION:  Kansas

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

         5.       SOLE VOTING POWER                  2,581,500  (See Item 4)

         6.       SHARED VOTING POWER                0

         7.       SOLE DISPOSITIVE POWER             2,581,500  (See Item 4)

         8.       SHARED DISPOSITIVE POWER           0

9.       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:
         2,581,500  (See Item 4)

10.      CHECK IF THE AGGREGATE AMOUNT IN ROW 9 EXCLUDES CERTAIN SHARES:   [ ]

11.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9:    11.0%

12.      TYPE OF PERSON REPORTING: IA





CUSIP No. 45068B109                 13G

1.       NAME OF REPORTING PERSON (S.S. or I.R.S. Identification No. of
         Above Person)

         Waddell & Reed, Inc.  Tax ID No. 43-1235675

2.       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP:

         (a)      [ ]
         (b)      [ ]

3.       SEC USE ONLY

4.       CITIZENSHIP OR PLACE OF ORGANIZATION: Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

         5.       SOLE VOTING POWER                  2,581,500  (See Item 4)

         6.       SHARED VOTING POWER                0

         7.       SOLE DISPOSITIVE POWER             2,581,500  (See Item 4)

         8.       SHARED DISPOSITIVE POWER           0

9.       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:
         2,581,500  (See Item 4)

10.      CHECK IF THE AGGREGATE AMOUNT IN ROW 9 EXCLUDES CERTAIN SHARES:    [ ]

11.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9:  11.0%

12.      TYPE OF PERSON REPORTING:  BD





CUSIP No. 45068B109                 13G

1.       NAME OF REPORTING PERSON (S.S. or I.R.S. Identification No. of
         Above Person)

         Waddell & Reed Financial Services, Inc.  Tax ID No. 43-1414157

2.       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP:

         (a)      [ ]
         (b)      [ ]

3.       SEC USE ONLY

4.       CITIZENSHIP OR PLACE OF ORGANIZATION:  Missouri

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

         5.       SOLE VOTING POWER                  2,581,500  (See Item 4)

         6.       SHARED VOTING POWER                0

         7.       SOLE DISPOSITIVE POWER             2,581,500  (See Item 4)

         8.       SHARED DISPOSITIVE POWER           0

9.       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:
         2,581,500  (See Item 4)

10.      CHECK IF THE AGGREGATE AMOUNT IN ROW 9 EXCLUDES CERTAIN SHARES:   [ ]

11.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9:  11.0%

12.      TYPE OF PERSON REPORTING: HC





CUSIP No. 45068B109                 13G

1.       NAME OF REPORTING PERSON (S.S. or I.R.S. Identification No. of
         Above Person)

         Waddell & Reed Financial, Inc.  Tax ID No. 51-0261715

2.       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP:

         (a)      [ ]
         (b)      [ ]

3.       SEC USE ONLY

4.       CITIZENSHIP OR PLACE OF ORGANIZATION:  Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

         5.       SOLE VOTING POWER                  2,581,500  (See Item 4)

         6.       SHARED VOTING POWER                0

         7.       SOLE DISPOSITIVE POWER             2,581,500  (See Item 4)

         8.       SHARED DISPOSITIVE POWER           0

9.       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON:
         2,581,500  (See Item 4)

10.      CHECK IF THE AGGREGATE AMOUNT IN ROW 9 EXCLUDES CERTAIN SHARES:   [ ]

11.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9:  11.0%

12.      TYPE OF PERSON REPORTING:  HC





ITEM 1(a):        NAME OF ISSUER:  ITT Educational Services, Inc.
---------         --------------

ITEM 1(b):        ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES:
---------         -----------------------------------------------

                  5975 Castle Creek Parkway N Drive
                  P.O. Box 50466
                  Indianapolis, IN  46250

ITEM 2(a):        NAME OF PERSON FILING:
---------         ---------------------

                  (i)      Waddell & Reed Financial, Inc.
                  (ii)     Waddell & Reed Financial Services, Inc.
                  (iii)    Waddell & Reed, Inc.
                  (iv)     Waddell & Reed Investment Management Company

ITEM 2(b):        ADDRESS OF PRINCIPAL BUSINESS OFFICE:
---------         ------------------------------------

                  (i)-(iv):         6300 Lamar Avenue
                                    Overland Park, KS  66202

ITEM 2(c):        CITIZENSHIP:
---------         -----------

                  (i), (iii): Delaware
                  (ii):  Missouri
                  (iv):  Kansas

ITEM 2(d):        TITLE OF CLASS OF SECURITIES:  Common Stock
---------         -----------------------------

ITEM 2(e):        CUSIP NUMBER:  45068B109
---------         ------------

ITEM 3:           The reporting person is:
------

                  (i)      Waddell & Reed Financial, Inc., a parent holding
                           company in accordance with Reg.
                           240.13d-1(b)(1)(ii)(G);
                  (ii)     Waddell & Reed Financial Services, Inc., a parent
                           holding company in accordance with
                           Reg. 240.13d-1(b)(1)(ii)(G);
                  (iii)    Waddell & Reed, Inc., a broker-dealer in accordance
                           with Reg. 240.13d-1(b)(1)(ii)(A);
                           and
                  (iv)     Waddell & Reed Investment Management Company, an
                           investment advisor in accordance with
                           Reg. 240.13d-1(b)(1)(ii)(E).

ITEM 4:           OWNERSHIP
---------         ---------

                  The securities reported on herein are beneficially owned by
one or more open-end investment companies or other managed accounts which are
advised or sub-advised by Waddell & Reed Investment Management Company
("WRIMCO"), an investment advisory subsidiary of



Waddell & Reed, Inc. ("WRI"). WRI is a broker-dealer and underwriting subsidiary
of Waddell & Reed Financial Services, Inc., a parent holding company ("WRFSI").
In turn, WRFSI is a subsidiary of Waddell & Reed Financial, Inc., a publicly
traded company ("WDR"). The investment advisory contracts grant WRIMCO all
investment and/or voting power over securities owned by such advisory clients.
The investment sub-advisory contracts grant WRIMCO investment power over
securities owned by such sub-advisory clients and, in most cases, voting power.
Any investment restriction of a sub-advisory contract does not restrict
investment discretion or power in a material manner. Therefore, WRIMCO may be
deemed the beneficial owner of the securities covered by this statement under
Rule 13d-3 of the Securities Exchange Act of 1934 (the "1934 Act").

         WRIMCO, WRI, WRFSI and WDR are of the view that they are not acting as
a "group" for purposes of Section 13(d) under the 1934 Act. Indirect "beneficial
ownership" is attributed to the respective parent companies solely because of
the parent companies' control relationship to WRIMCO.

                  (a)   Amount beneficially owned:  2,581,500

                  (b)   Percent of class:  11.0%

                  (c)   Number of shares as to which the person has:

                        (i)    Sole voting power to vote or to direct the vote:

                               WDR:  2,581,500 (indirect)
                               WRFSI:  2,581,500 (indirect)
                               WRI:  2,581,500 (indirect)
                               WRIMCO:  2,581,500 (direct)

                        (ii)   Shared power to vote or to direct the vote:  0

                        (iii)  Sole power to dispose or to direct the
                               disposition of:

                               WDR:  2,581,500 (indirect)
                               WRFSI:  2,581,500 (indirect)
                               WRI:  2,581,500 (indirect)
                               WRIMCO:  2,581,500 (direct)

                        (iv)   Shared power to dispose or to direct the
                               disposition of:  0

ITEM 5:           OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS:
------            --------------------------------------------

                  If this statement is being filed to report the fact that as of
the date hereof the reporting person has ceased to be the beneficial owner of
more than 5 percent of the class of securities, check the following: [ ]




ITEM 6:           OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER
------            -------------------------------------------------------------
                  PERSON:
                  ------

                  The clients of WRIMCO, including investment companies
registered under the Investment Company Act of 1940 and other managed accounts,
have the right to receive dividends from as well as the proceeds from the sale
of such securities.

ITEM 7:           IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH
------            -------------------------------------------------------------
                  ACQUIRED THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING
                  -------------------------------------------------------------
                  COMPANY:
                  --------

                  See Attached Exhibit 2.

ITEM 8:           IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP:
------            ---------------------------------------------------------

                  Not Applicable.

ITEM 9:           NOTICE OF DISSOLUTION OF GROUP:
------            ------------------------------

                  Not Applicable.




Item 10:          Certification:

                  By signing below I certify that, to the best of my knowledge
and belief, the securities referred to above were acquired and are held in the
ordinary course of business and were not acquired and are not held for the
purpose of or with the effect of changing or influencing the control of the
issuer of the securities and were not acquired and are not held in connection
with or as a participant in any transaction having that purpose or effect.

                                    SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.

Dated:   April 9, 2001


Waddell & Reed Financial, Inc.      Waddell & Reed Financial Services, Inc.

By: /s/ Daniel C. Schulte           By: /s/ Wendy J. Hills

Name: Daniel C. Schulte             Name: Wendy J. Hills
Title:  Vice President              Title:  Attorney-In-Fact


Waddell & Reed, Inc.                Waddell & Reed Investment Management Company

By:  /s/ Wendy J. Hills             By:  /s/ Wendy J. Hills

Name: Wendy J. Hills                Name: Wendy J. Hills
Title: Attorney-In-Fact             Title: Attorney-In-Fact





                                  EXHIBIT INDEX


Exhibit
  No.            Description
              
  1              Joint Filing Agreement

  2              Identification and Classification of the Subsidiary Which
                 Acquired the Security Being Reported on by the
                 Parent Holding Company

  3              Power of Attorney