The Cancer and Leukemia Group B Genitourinary (GU) Committee has developed a multidisciplinary approach to treatment of GU cancer and has integrated correlative science research into the major research themes of the GU Committee. In localized prostate cancer, trials have evaluated novel approaches in radiation therapy. For patients with recurrence after local therapy, a trial evaluating local recurrence with salvage prostatectomy and a study of systemic therapy with "peripheral androgen blockade" were undertaken. Major contributions have been made in developing and testing therapeutics for advanced, androgen-independent prostate cancer (ketoconazole, suramin, estramustine/docetaxel, and docetaxel/bevacizumab), and in developing predictive markers and algorithms to assess prognosis in these patients. Contributions in kidney cancer have included the development of novel trial methodology, such as the randomized discontinuation trial design, and the testing of antiangiogenics. In addition to these areas, future work of the committee will include further development of therapy for earlier-stage prostate cancer patients and bladder cancer patients.