Prostate cancer (PCa) ranks as the second most common cancer in Japanese males, while bladder cancer (BC) holds the tenth spot. Among double urological cancers, the incidence of synchronous or metachronous BC and PCa is the highest. Reports on upper urinary tract (UUT) urothelial cancer (UC) in PCa patients are limited. Here, we present three cases of metachronous PCa and BC, with subsequent diagnosis of ureteral and renal pelvic cancer during the course of the disease. In the follow-up of patients with urological cancers, it is important to be aware not only of the progression of the initial cancer but also the potential development of a second cancer.