This study was designed to evaluate the efficacy of surgical resection of the primary tumor and lymph nodes in patients with localized small-cell carcinoma who had responded to induction chemotherapy. The study was performed in 37 patients who received two cycles of chemotherapy consisting of cyclophosphamide, doxorubicin, and etoposide. Those patients who achieved a complete or partial (greater than 50%) response were evaluated for thoracotomy and the primary tumor and regional lymph nodes excised when feasible. Postoperatively, the patients received prophylactic cranial irradiation and were maintained on the same chemotherapy for an average of 11 months. Twelve patients were resected and found to have residual small-cell carcinoma in the operative specimen (ten) or no residual disease (two). Seven of these patients (58%) are alive without evidence of disease (median follow-up, 24 months). Seven other patients who were resected proved to have either residual foci or small-cell carcinoma mixed with adenocarcinoma or large-cell carcinoma (four) or only focal areas of adenocarcinoma, large-cell carcinoma, or squamous-cell carcinoma with no evidence of residual small-cell carcinoma. Five of these patients (71%) are alive without evidence of disease (median follow-up, 36 months). Two of the 16 patients who were not resected but treated with chemotherapy and radiation are alive at 15 and 31 months without evidence of disease, the other 14 are dead of disease.