Forty-two patients with advanced cancer of the prostate were prospectively randomized to receive either bacillus Calmette-Guerin (BCG) adjuvant immunotherapy plus conventional therapy or conventional therapy alone. Conventional therapy consisted of estrogens or observation. There was a statistically significant (P = less than 0.05) longer survival in the 21 BCG-treated patients (thirty-eight weeks) than in the 21 control patients (twenty-eight weeks). There was no mortality and minimal morbidity (pruritus at injection site) from the adjuvant immunotherapy. Interestingly, the quality of life, as measured by the number of infections, was significantly less (P = less than 0.05) in the immunotherapy-treated group.