We have defined "clinical N2" disease in non-small cell lung cancer to mean the presence of enlarged metastatic mediastinal nodes evident on plain chest roentgenograms or widening of the carina at bronchoscopy. Forty-one patients with non-small cell carcinoma of the lung and clinical N2 M0 disease presumed operable received 2 to 3 cycles of high-dose cisplatin with vindesine (or vinblastine sulfate) with or without mitomycin-C. Following chemotherapy, 30 patients (73%) had a major radiographic response. Of these patients, 28 had thoracotomy, and 21 (75%) of them had complete resection of the disease, 8 of whom had total sterilization of the tumor proven histologically. An additional 4 patients had limited microscopic foci of residual tumor either in lung or lymph nodes. Survival at 3 years from diagnosis was 34% for all patients, 40% for those who completed the combined treatment (chemotherapy and surgery), and 54% for those who had complete resection with a median follow-up of 44 months and a median survival not yet attained.