Chemotherapy is currently a primary treatment modality for small-cell lung cancer (SCLC). However, in the limited stage, a combination of chemotherapy and thoracic irradiation (TI) was found to be superior to chemotherapy alone by meta-analysis. Recently, concurrent administration of cisplatin and etoposide with TI may be an optimal treatment. The usefulness of prophylactic cranial irradiation in complete responders was also confirmed by meta-analysis. Dose-intensive weekly chemotherapy failed to improve the treatment outcome in the extensive stage. Randomized trials to verify the effectiveness of high-dose chemotherapy with peripheral blood stem cell transplantation are in progress.