Patients with end-stage renal failure due to analgesic nephropathy have an increased risk of developing a urothelial carcinoma. To determine the impact of renal transplantation on the frequency of urothelial carcinomas, we analyzed 2072 patients who underwent 2371 renal transplantation between 1968 and 1993, including 78 (3.8%) with clinically proven analgesic nephropathy. Before and after transplantation a regular tumor screening was performed in patients with analgesic nephropathy by urine cytology and abdominal sonography. In 11 of the 78 patients with analgesic nephropathy (14.1%; age 51-66 years, 40-108 months after initiation of dialysis treatment, 5-77 months after transplantation), a urothelial carcinoma of the native urinary tract, especially the kidneys, was diagnosed. Therapy comprised nephroureterectomy (n = 6), transurethral resection (n = 6) and/or cystectomy (n = 2). Seven patients died due to tumor progression 16.3 (4-33) months postoperatively and one patient died due to a perioperative complication. Despite regular tumor screening after transplantation, the diagnosis of a urothelial carcinoma was made very late, leading to a high tumor-related mortality. As a consequence, we suggest that a bilateral nephroureterectomy should be performed prophylactically in patients with proven analgesic nephropathy. In addition, a cystoscopy with lavage cytology testing of the bladder should be performed twice a year.