While androgen deprivation has remained the cornerstone of therapy for advanced prostate cancer over the last 60 years, novel therapies are being developed that may expand upon currently available treatments. The identification of antigens expressed by prostate tissue and/or prostate cancer that are recognized by T cells creates opportunities to develop novel immunotherapeutic approaches, including tumor vaccines. Improved understanding of immune recognition and antigen presentation may lead to effective immunotherapies for prostate cancer. Identified proteins expressed in prostate cancer, including prostate-specific antigen (PSA), prostatic acid phosphatase (PAP), and prostate-specific membrane antigen (PSMA), have been used as immunologic targets for immunotherapy. Moreover, innovations in cancer genomics and proteomics will also aid in the identification of immunologic targets. Immunotherapy trials have already demonstrated evidence of not only immunogenicity, but also clinical efficacy, and future studies will be directed at capitalizing on these findings.