Twenty-five patients with stage III, non-small cell lung cancer were treated with cisplatin-based chemotherapy and thoracic radiation therapy followed by surgery. Thirteen patients had stage IIIA disease and 12, stage IIIB disease. The chemotherapy and radiotherapy were intensively combined with only a few days' interval between them. Radiation therapy delivering a total dose of 50-70 Gy was started 10 days after the beginning of chemotherapy. A few additional courses of chemotherapy were repeated until a thoracotomy was performed. All but two surgically-treated patients underwent tumor resection, with 19 lobectomies and four pneumonectomies. Eighteen patients underwent curative and five, non-curative resections. Pathological examination of the resected specimen provided accurate intrathoracic information. Six patients (24%) showed a pathologically complete response, with no cancer cells detected in the resected specimens. Severe postoperative complications occurred in five patients (20%), with one death. The disease recurred in five of the 18 patients who underwent a curative resection. A second primary tumor developed in two other patients. Seventeen patients (68%) are alive, with a median follow-up of 37 months after thoracotomy. The estimated three-year survival was 67% for all patients.