A phase II trial of etoposide and cisplatin for patients with previously treated small cell lung cancer was carried out by CALGB from June 1983 to May 1984. Thirty-five evaluable patients who had failed one prior chemotherapy regimen were treated with etoposide 80 mg/m2 and cisplatin 20 mg/m2 days 1-5 every 3 weeks. Objective responses were seen in 7 patients (20%) with 1 complete response and 6 partial responses. The median duration of response was 5.1 months. Fifteen patients (43%) had stable disease. Overall survival was 49% at 6 months and 14% at 1 year. The median survival was 6 months. Toxicity was mainly hematologic with severe and life-threatening leukopenia and thrombocytopenia seen in 71% and 66% of patients, respectively. Two treatment-related deaths caused by infection were seen. This cooperative group study fails to confirm the high response rates previously reported in institutional pilot studies.