Patients with prostate cancer increasingly use complementary and alternative therapies. A well-informed oncologist can guide patients to use such treatments to maximize their benefits and reduce the risk of harm. Patients should be dissuaded from using alternative therapies instead of mainstream care to treat cancer. Preliminary evidence suggests that botanical medicines such as PC-SPES may be of benefit, but comparative human trials are yet to be conducted and problems of contamination resolved. Some complementary therapies help reduce symptoms in early-stage prostate cancer, but botanical remedies must be treated with caution because of the possibility of adverse effects and interactions with conventional medicine.