Prostate cancer is the most commonly diagnosed malignancy in united States males. Unfortunately, numerous controversies surround clinical management for early stage disease and the utility of population screening. Much of this controversy stems from the lack of knowledge about the biology of prostate cancer, including the lack of clearly defined risk factors, absence of markers indicative of aggressive clinical behavior, as well as a lack of a clear understanding of its underlying genetic features. This paper reviews currently available evidence regarding the genetic characteristics of adenocarcinoma of the prostate, including the impact of family history of disease risk, the nature of structural genetic aberrations, and the possible role of oncogenes and tumor suppressor genes in its pathogenesis. A clearer understanding of these issues will hopefully lead to more effective and rational treatment policies in addition to the development of effective disease prevention strategies.