Patients with hormone-naive stage D2 prostate cancer often benefit from castration. This treatment, however, frequently produces many unacceptable physical and psychological side effects, especially in younger and sexually active patients. Bicalutamide is an oral antiandrogen with excellent tolerance and preservation of sexual function. Three institutions participated in phase II and III trials of bicalutamide monotherapy (50 mg daily) as primary therapy in hormone-naive patients with stage D2 prostate cancer. Upon bicalutamide failure, all patients underwent castration and were followed until death. Fifty-four patients received bicalutamide 50 mg orally once a day. One patient (2%) had complete response, 9 patients (17%) had partial response, and 27 patients (50%) had stable disease. Seventeen patients (31%) had progressive disease. The median time to bicalutamide failure was 47.4 weeks, 70.5 weeks for the responders vs. 25.4 weeks for the nonresponders (p < 0.001). The median survival time after the sequential use of bicalutamide and castration was 119.2 weeks for all 54 patients, 162.0 weeks for the responders, and 73.5 weeks for nonresponders (p < 0.0001). The median survival time after initiation of castration was 71.1 weeks for all 54 patients, 91.4 weeks for bicalutamide responders, and 42.1 weeks for nonresponders (p < 0.01). In hormone-naive patients with stage D2 prostate cancer, sequential treatment with bicalutamide monotherapy followed by castration upon failure may produce survival time within the range reported for initial treatment with castration. Thus, considering the favorable quality of life profile of bicalutamide, further studies are needed to define the role of sequential hormonal therapy in younger sexually active patients.