Prostate cancer is the most frequently diagnosed malignancy and the second leading cause of cancer deaths in American men. Although many treatment measures such as androgen deprivation, radiation therapy, and cryoablation exist for primary prostate cancer, there is currently no effective treatment for patients presenting advanced or metastatic stages of the disease. Molecular therapy offers an attractive approach to the treatment of primary prostate cancer because the prostate is not a life-sustaining organ, and a number of tissue specific promoters can be used for prostatic gene expression following relatively straightforward delivery routes. This review discusses the general molecular therapy applications in the context of prostate cancer, and most importantly, identifies the prostate apoptosis response-4 (Par-4) gene, which exclusively induces apoptosis in cancer cells and not normal cells, as a prospective molecule for therapy of the disease.