Benign prostatic hyperplasia (BPH) is the most common non-malignant neoplasm in the aging male. Primarily treated surgically in the past, the costs, complications and outcome of this treatment has spurned interest in medical management. The primary objective of this study is to critically evaluate pharmacological strategies for the treatment of symptomatic BPH. In particular, to determine the efficacy of alpha blockade (terazosin), androgen suppression (finasteride), and the combination of alpha blockade and androgen suppression for the treatment of men with symptomatic bladder outlet obstruction secondary to BPH. Other areas to be investigated include the ability of the above agents to delay or prevent progression of the disease, the relationship between prostate size and regression of symptoms, the ability of objective diagnostic and pathologic studies to determine which patients are better candidates for pharmacologic therapy, and determining at which stage of prostatic growth or symptoms it is best to intervene pharmacologically. The primary goal of this application is to demonstrate the ability of Yale University School of Medicine and the Yale-New Haven Hospital to successfully implement this protocol such that quality data is obtained to achieve the goals of the above stated proposal. The advantages of this site include: 1) investigators with recent experience in successfully implementing a similar protocol; 2) an institution with the necessary infrastructure and experience in participating in large multicenter protocols; 3) the presence of the university in an ethnically and socioeconomically diverse community, which will allow utilization of peripheral sites in these communities so that their inclusion is maximized; and 4) an established basic science laboratory skilled in many techniques which could be utilized for future studies of BPH, specifically immunohistochemical localization of various antigens. Recruitment strategies will include; 1) utilization of local media outlets such as newspapers, radio and television stations, specifically those targeting minority populations; 2) utilizing the peripheral sites, their staff and physicians to maximize enrollment by the population served; 3) soliciting participation from primary care physicians and urologists in the area who are not affiliated with any of the peripheral sites; and 4) speaking to various community organizations (i.e. churches and clubs) to increase public awareness. Subject follow-up will be encouraged by providing each with wallet sized information cards detailing return appointments, the presence of a daily central on-site nurse to maximize convenience, following subjects at two peripheral sites, travel and parking reimbursement, and a small financial incentive provided for each year of follow-up. The above characteristics and strategies make the Yale University School of Medicine and the Yale-New Haven Hospital an excellent candidate for a Clinical Center.