Prostate cancer prevention is now one of the most aggressively investigated areas of urologic oncology, with > 30,000 men currently participating in clinical trials in the United States alone. The Prostate Cancer Prevention Trial will complete end-of-study prostate biopsies in May 2004, and the Selenium and Vitamin E Cancer Prevention Trial is rapidly reaching its accrual goal 1-2 years ahead of schedule. These 2 studies will give definitive answers regarding 3 of the most important potential preventive interventions: finasteride, vitamin E, and selenium. Many phase II and biomarker-modulation studies are also ongoing, testing a host of other interventions. It is hoped that, within a short period of time, the clinician will be provided with strategies to reduce the risk of the disease.