A peptide vaccine containing a human Wilms tumor 1 (WT-1) protein-derived epitope with potential antineoplastic activity. Vaccination with the WT-1 analog peptide vaccine may induce a cytotoxic T-lymphocyte (CTL) response against WT-1 expressing cells, resulting in tumor cell lysis and inhibition of tumor cell proliferation. WT-1, a zinc finger transcription factor, is overexpressed in most types of leukemia and in some solid cancers.