Prostate cancer is a prevalent disease, and it is an ideal target for chemoprevention because of its high incidence and long latency. Selenium, a cofactor for an antioxidant, has been shown to increase apoptosis and decrease cell number in prostate cancer cells (10). These effects are surprising because they occur at the level of gene expression, and they appear to be independent to selenium’s role as an antioxidant. Clark’s study in 1996 first proposed the idea of selenium as a chemopreventive element for prostate cancer, and various in vivo and in vitro studies support his findings (7). However, some argue that only patients will low baseline levels of selenium decrease their risk for prostate cancer through selenium. The SELECT study is a 12-year study aimed at elucidating these results, but current research supports the claim that patients with a low baseline level of selenium benefit from supplementation. Selenium obtained from natural dietary sources and multivitamins appears more advantageous at this point because there are questions of an increased risk of prostate cancer related to too much selenium. In spite of this risk, selenium offers an important potential alternative to standard therapy.