From November, 1986 to October, 1989, the antitumor activities of several chemotherapeutic agents were tested by subrenal capsule assay (SRCA) in cases of 23 transitional cell carcinomas. Overall sensitivities of tested drugs to transitional cell carcinomas were compatible to clinical data and correlated with individual clinical courses. This method has some problems, but can be carried out at any institute and serve as an aid to the selection of chemotherapeutic agents.