The toxicity and efficacy of concomitant chemotherapy and radiotherapy as induction therapy was evaluated in patients with previously untreated small cell carcinoma of the lung (SCLC), and in responding patients the value of maintenance chemotherapy was examined. 202 patients received induction chemotherapy with cisplatin and etoposide (EP), in combination with cranial and local radiotherapy. 85 patients (42%) developed grades III and IV myelosuppression, the main toxicity of induction treatment. Of the 154 responding patients, 129 were randomised to maintenance chemotherapy with vincristine, doxorubicin and cyclophosphamide (VAC) or no further treatment. The response rate for the limited disease patients (LD) was 87%, 62% achieving a complete response (CR) and the response rate for extensive disease patients (ED) was 68%, with 26% achieving a CR. 17 patients (11%) completed 10 courses of maintenance chemotherapy. 32 patients (57%) developed grade III and IV neutropenia. Median survival for all patients was 53 weeks (LD, 70 weeks; ED, 42.5 weeks). There was no significant difference in overall survival (OS) or disease-free survival (DFS) in the two randomisation arms. This study shows that EP combined with radiotherapy is an effective induction regimen in SCLC. Maintenance chemotherapy with VAC is not associated with increased survival but has significant toxicity after such induction treatment.