<Page>

                                                                    EXHIBIT 32.1

                  CERTIFICATION OF PRINCIPAL FINANCIAL OFFICER
                           PURSUANT TO 18 U.S.C. 1350
                 SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

    I, John P. Saldarelli, Treasurer and Chief Financial Officer (Principal
Financial Officer) of American Property Investors, Inc., the General Partner of
American Real Estate Partners, L.P. (the 'Registrant'), certify that to the best
of my knowledge, based upon a review of the American Real Estate Partners, L.P.
Quarterly Report on Form 10-Q for the period ended June 30, 2003 of the
Registrant (the 'Report'):

        (1) The Report fully complies with the requirements of Section 13(a) or
    15(d) of the Securities Exchange Act of 1934, as amended; and

        (2) The information contained in the Report fairly presents, in all
    material respects, the financial condition and results of operations of the
    Registrant.

                                                /s/ JOHN P. SALDARELLI
                                          .....................................
                                                    JOHN P. SALDARELLI
                                          TREASURER AND CHIEF FINANCIAL OFFICER
                                            AMERICAN PROPERTY INVESTORS, INC.,
                                                  THE GENERAL PARTNER OF
                                           AMERICAN REAL ESTATE PARTNERS, L.P.

Date: August 14, 2003