From January 1982 to October 1987, 100 patients with multifocal superficial bladder cancer received intravesical MMC at the Institute of Urology, University of Padova. Seventy-three patients had papillary multifocal superficial bladder carcinoma (stages Ta-T1): treatment was divided into therapeutic (18 cases), and prophylactic (55 cases). 27 patients had carcinoma in situ. 39 patients affected by neoplasia relapsed to previous intravesical ADM treatment. All patients received 40 mg. intravesical MMC weekly for 8 consecutive weeks, repeating the cycle in cases of relapse. Complete response rates at 12 months was 53%, 50 to 67% for each group, respectively. Recurrence rate was lower compared to that before treatment; progression rate was also lower compared to a group who received only endoscopic treatment. In patients who relapsed with ADM treatment, the percentage of complete response was 69%. We underscore the efficacy of MMC in lowering relapse and progression in multifocal superficial bladder cancer, which represents the best indication for this kind of treatment.