Based upon the schedule specificity of etoposide and the in vitro and clinical synergy observed with cisplatin, the Eastern Cooperative Oncology Group conducted a phase II trial of oral etoposide and cisplatin in newly diagnosed, untreated patients with extensive stage small cell carcinoma of the lung. 35 patients received 100 mg/m2 of cisplatin intravenously on day 1 and 50 mg/m2 of etoposide orally for 21 consecutive days. Cycles were repeated every 28 days. The most common toxicity observed was myelosuppression. Sixty-seven per cent of patients had grade 3 or 4 leukopenia and 34% had grade 3 or 4 thrombocytopenia during cycle one. Of 26 evaluable patients, 4 had a complete response (15%) and 17 had a partial response (65%). The median survival for the group as a whole was 8.5 months. We conclude that this regimen was associated with significant myelosuppression, and offered no therapeutic advantage to other commonly administered chemotherapeutic regimens for small cell carcinoma of the lung.