A peptide vaccine consisting of 10 synthetic long peptides (SLPs), 25-30 amino acids in size and derived from the middle portion of p53 (amino acids 70-251), mixed with the adjuvant Montanide ISA-51 with potential immunostimulatory and antitumor activities. Upon administration, p53 synthetic long peptide (70-251) vaccine may stimulate the host immune system to mount a cytotoxic T-cell lymphocyte (CTL) response against p53-expressing tumor cells. p53, a tumor associated antigen (TAA), may be overexpressed in variety of cancer cell types.