Benign prostatic hyperplasia (BPH) is a common problem among aging men that produces significant morbidity and health care costs. Contention exists as to whether currently available surgical and pharmacologic options for BPH are appropriate for men in the watchful-waiting stage. Recently, the possible benefits of phytotherapies (plant-derived preparations) in treating BPH and prostate cancer are being considered. Several phytotherapies, including saw palmetto, Pygeum africanum, curbicin, and isoflavone-containing supplements (red clover [Trifoleum pratense] and soy), are widely used in patients with BPH. Evidence suggests that the consumption of isoflavones found in legumes is related to lower rates of BPH and prostate cancer among Asian men. When evaluating natural therapies, the physician should look for a product that relieves symptoms and is safe, contains a health-conferring ingredient with a defined mechanism of action, and is standardized for that ingredient. Phytotherapies, particularly isoflavone-containing supplements, are likely to have an important role in the management of patients in the watchful-waiting stage of BPH.