INTRODUCTION: If an agent can slow the growth of existing prostate cancer cells, it remains plausible that it may be effective as an adjunct to surgery, radiation or chemotherapy. DISCUSSION: Level-1 evidence will be needed in order to definitively prove the efficacy of agents as chemoprevention strategies for prostate cancer. Currently, only finasteride fulfills this criterion. Two major trials are underway that will assess the role of soy, vitamin E and selenium in prostate cancer prevention. CONCLUSION: Tantalizing prospects for effective chemoprevention of prostate cancer exist. Fortunately, well-conducted randomized trials will allow us to answer many of these questions within the next 2 to 8 years.