A cancer vaccine consisting of an immunogenic peptide derived from the cancer-testis antigen (NY-ESO-1), an antigen found in normal testis and various tumors. Vaccination with NY-ESO-1 peptide vaccine may stimulate the host immune system to mount a humoral and cytotoxic T lymphocyte (CTL) response to cells expressing NY-ESO-1 antigen, resulting in tumor cell lysis.