Eighteen evaluable patients with metastatic or recurrent renal cell carcinoma were treated with carboplatin. Fourteen patients received 400 mg/m2 as the initial dose, and four patients received reduced doses based on prior radiation therapy and/or elevated serum creatinine. No responses were seen. Median survival of these 18 patients was 8.3 months. Risk group status which previously has been identified as an important indicator of survival was predictive for survival in this study. Patients in the most favorable risk groups had a median survival of 21.2 months vs. 6.6 months for the most unfavorable risk groups. No lethal toxicities occurred with the administration of carboplatin; however, 66% of patients received doses of sufficient magnitude to cause severe or life threatening thrombocytopenia or anemia.