UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549


                                    Form 8-K


                                 Current Report

     Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934


       Date of Report (Date of earliest event reported): January 22, 2004


                             KLA-Tencor Corporation
             (Exact name of registrant as specified in its charter)


                                    000-09992
                            (Commission File Number)


         Delaware                                      04-2564110
- ----------------------------                       -------------------
(State or other jurisdiction                        (I.R.S. Employer
     of incorporation)                             Identification No.)

                                 160 Rio Robles
                              San Jose, California
                                      95134
             (Address of principal executive offices, with zip code)


                                 (408) 875-3000
              (Registrant's telephone number, including area code)


                                       N/A
          (Former name or former address, if changed since last report)

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Item 7. Financial Statements and Exhibits.

     (c)  Exhibits.

Exhibit   Description
- -------   -----------

 99.1     Press Release issued by KLA-Tencor Corporation dated January 22, 2004.

Item 12. Results of Operations and Financial Condition

     On January 22, 2004, KLA-Tencor  Corporation,  (the "Company") is issuing a
press release and holding a conference call regarding its financial  results for
the quarter and six months ending December 31, 2003. A copy of the press release
is furnished as Exhibit 99.1 to this Form 8-K.

     The information in this Form 8-K and the exhibit  attached hereto shall not
be deemed "filed" for purposes of Section 18 of the  Securities  Exchange Act of
1934, as amended (the "Exchange  Act"), or otherwise  subject to the liabilities
under that  section,  nor shall it be deemed  incorporated  by  reference in any
filing  under the  Securities  Act of 1933,  as amended,  or the  Exchange  Act,
regardless of any general incorporation language in such filing.

                                       -2-


================================================================================

                                   SIGNATURES

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

                                              KLA-TENCOR CORPORATION


Date:  January 22, 2004                       By:  /s/ John H. Kispert
                                                   -------------------
                                                   John H. Kispert
                                                   Executive Vice President
                                                   and Chief Financial Officer


INDEX TO EXHIBITS

Exhibit   Description
- -------   -----------

 99.1     Press Release issued by KLA-Tencor Corporation dated January 22, 2004.