Seven patients with recurring transitional cell carcinoma of the urinary bladder were treated with repeated transurethral resections of these tumors and were given adjuvant intravesical chemotherapy or bacillus-Calmette Guerin (BCG) vaccine. Carcinoma either in the ureters or renal pelves subsequently developed in these patients. Unfortunately, 2 patients had inoperable tumors when the diagnosis was confirmed. When treating patients with recurring carcinoma of the urinary bladder, the possibility of upper urinary tract tumors developing must always be considered. Hence, the necessity of frequent urinary and ureteral cytology examinations proceeding to excretory urography, retrograde pyelograms, computerized tomography (CT) scans of the upper tracts, or ureteroscopy as may be necessary to locate small tumors or to diagnose carcinoma in situ.