This proposal provides detailed information on, and plans for, a clinical trial center in the Departments of Urology and Preventive Medicine at the University of Iowa for the full-scale trial of medical therapy in benign prostatic hyperplasia . The planning for this clinical trial center has been performed to ensure the center's success in meeting the long-term objectives of the multicenter trial. Specifically, this proposal provides detailed information to establish our ability to meet recruitment goals including minority populations, ensure eligibility of participants, perform accurate and efficient protocol follow-up, perform timely data entry and completion, effectively communicate with the data coordinating center and diagnostic center, and maintain patient interest and compliance. In order to ensure the ability of the clinical center to meet the above specific aims, a multi-disciplinary research team has been organized for this trial. Members of this team have been recruited based upon extensive prior experience in clinical research, expertise in the diagnosis, management and treatment of male voiding dysfunction, and well-established skills in patient recruitment for large-scale clinical trials. This core research team, in concert with additional study personnel, has been organized in an efficient administrative structure intended to meet the above specific aims. Through this structure, well-established and refined marketing strategies targeted at the desired patient population will be implemented to meet work accrual goals. Two satellite clinics in areas of higher density minority populations will enhance our ability to recruit these patients as well as broaden the catchment area through which we might access participants. Fail-safe mechanisms are outlined which are intended to ensure our ability to meet accrual goals, perform accurate and efficient follow-up, enter data in a timely fashion, and provide quality information to the data coordinating center. In addition, we have outlined our strategy for maintaining patient compliance throughout the protracted follow-up course of this trial. In summary, this proposal reviews both the qualifications of this clinical trial center, as well as the specific manner in which this center will function for the trial of medical therapy in benign prostatic hyperplasia.