At the Institute of Urology, University of Padova, 125 patients with multifocal superficial bladder cancer underwent treatment with intravesical Mitomycin C (MMC; 1 weekly instillation of 40 mg for 8 consecutive weeks) between January 1982 and December 1988. Eighty-four patients had multifocal papillary tumors (stages Ta-T1) and 41 patients had carcinoma in situ of the bladder. At 6 and 36 months the tumor free percentage in the group with papillary tumors was 69 and 36%, respectively; for carcinoma in situ the complete response percentage at the same intervals was 80 and 36%. Thirty-one patients previously unsuccessfully treated with adriamycin did not show any difference compared to untreated ones. The authors emphasize the efficacy and low toxicity of intravesical MMC in multiple superficial bladder cancer. The possibility of long-term relapse suggests maintenance therapy.