The present invention relates to peptide vaccines, pharmaceutical compositions thereof, and associated methodologies that promote the immune-mediated regression of tumors expressing an onconeural antigen, e.g. a cdr-2 antigen, HuD antigen. The cancer peptide vaccines of the present invention are antigenic peptides capable of being faithfully presented on the MHC I complex of a target cell or antigen presenting cell. This external cellular presentation of these peptides promotes a specific cytotoxic T lymphocyte (CTL)-mediated immune response against tumor cells expressing these proteins, thereby, inducing immunological reactivity.