In a sample of 306 patients with superficial bladder tumors (Ta, Tl), 48 were affected by associated carcinoma in situ (TIS). We included 40 of them in a random program with Mitomycin C or Adriamycin, administered endovesically. We found that those patients with associated TIS whose progression rate had increased to 37.1% compared to 8.8% in the original series (p less than 0.01), had a worse prognosis. Besides, 10 of them required radical cystectomy. With this chemotherapy program, we achieved a high rate of complete response (70%), but its duration was limited by a recurrence rate of 42.9%, with a time free of disease of 26.2 months. In the whole group, the survival rate free of disease was 77.5%, with an average follow-up of 37.3 months. On the other hand, we found extravesical recurrences not only in the prostatic urethra (13; 32.5%) but also at the end of the ureter (3; 7.5%).