Given the current preference of many patients for an active role in decision-making regarding their care, the feasibility of patients making their own treatment choices was investigated, and the reasons for their selections were studied. Subjects comprised previously untreated Stage D prostate cancer patients for whom hormonal therapy was indicated. Thirteen institutions entered 159 patients into the study. After discussing treatment choices with their physicians, the patients took home a two-page letter explaining two options: surgical castration and therapy with Zoladex (goserelin acetate), a depot luteinizing hormone-releasing hormone (LHRH) analogue injected subcutaneously every twenty-eight days. Patients were encouraged to discuss the treatment choices with their families. After selecting a treatment approach, patients completed a "decision questionnaire" and then treatment was initiated. Of the 147 patients who completed baseline questionnaires, 78 percent selected Zoladex and 22 percent selected orchiectomy. The primary reason for selecting Zoladex included avoidance of surgery (36%), success of treatment (18%), convenience of the drug (10%), and physician's advice (10%). Patients chose surgery primarily because of convenience (32%) and success of treatment (29%). Three months later, patients and their wives completed another questionnaire, which assessed their satisfaction with their treatment choices. Ninety-three percent of patients and 91 percent of patients' wives indicated that they would select the same treatment again.