The effectiveness of buserelin, a luteinizing hormone-releasing hormone agonist, was tested in 28 patients with Stages C or D adenocarcinoma of the prostate. Of 24 evaluable patients, there were 13 partial responses (54%) by National Prostatic Cancer Project criteria, median duration greater than 6 months. Nine patients had stable disease (38%), median duration greater than 5 months, and only two patients progressed. Performance status improved in 38%, patient-scored pain improved in 46%, and quality of life improved in 57%. Symptoms occurring during treatment consisted of hot flashes, loss of libido, and impotence. A flare of symptoms was observed in only one patient, despite a transient 25% increase in testosterone in 36% of patients. Buserelin is an effective treatment for inducing frequent and meaningful remissions in advanced prostatic cancer.