We analyzed the clinical features of multiple primary cancers arising from the urogenital organs. Between January 1980 and December 1999, 300 patients with renal cell carcinoma (RCC), 661 patients with urothelial carcinoma (bladder cancer and renal pelvic-ureteral cancer) (TCC) and 391 patients with prostate cancer (PC) were treated at our hospital. Of these patients, 20 patients had double genitourinary cancers. The double cancers consisted of RCC and TCC in 1 case, RCC and PC in 6 cases, and TCC and PC in 13 cases. Seven cases had synchronous tumors. The average interval in the metachronous cases was 68 (range: 12-209) months. The age at diagnosis of the second cancer was 68-94 (mean: 77.6) years old. The follow-up period ranged from 4-168 (mean: 38) months; Six patients are alive with no evidence of disease and 6 patients died of cancer. Even when limited to the urological section, the frequency of multiple primary cancers is increasing.