The prognosis for advanced cancer of the bladder remains poor. It is felt that further advances might reside in the utilization of chemotherapy; however there is a paucity of clinical data upon which to select active drugs. In an attempt to provide this information we are evaluating the effectiveness of a variety of antineoplastic agents on the recently developed N- 4-(5-nitro-2-furyl)-2-thiazylyl formanide (FANFT) induced bladder tumors in syngeneic mice. Tumors are induced in a high incidence of mice ingesting FNAFT and they resemble their human counterpart both grossly and histologically. These transitional cell tumors have been successfully transplanted and their responsiveness to chemotherapeutic agents evaluated. Initial evaluation has been performed by studying the activity of eleven different agents against a transplanted transitional cell tumor, MBT-2. Cyclophosphamide, cis-diamminedichloro platinum, adriamycin, and dactinomycin provided both significant reduction in tumor growth and prolongation of the median survival time. Appropriate drug combinations were more effective than single agents. Single and combinations are being evaluated in primary tumors by initiating chemotherapy in mice ingesting FANFT. Initial studies indicate that the drugs effective in the transplanted tumors markedly reduce the size of these primary tumors. These studies are being extended by initiating treatment earlier to determine whether chemotherapy can delay or possibly prevent these carcinogen induced neoplasms.