Advanced renal cell carcinoma is relatively resistant to most adequately evaluated chemotherapeutic agents. The combination of CCNU and vinblastine, which has antitumor activity in a frog renal carcinoma model system, has demonstrated activity in initial studies in man. The current study investigated this combination of drugs together with a progestational agent, Delalutin. Seventeen patients with metastatic renal cell carcinoma were treated with CCNU, vinblastine and Delalutin. There were no objective responses. Four patients with stable disease had a mean survival of 18 months compared to 13 patients with progressive disease who had a mean survival of 5 months. The survival of the four patients with stable disease was in large part due to the slowly progressive natural history of their disease.