Mediastinal lymph node dissection in conjunction with pulmonary resection was performed on 437 patients with bronchogenic carcinoma at the University of Michigan Medical Center from 1959 to 1969. The absolute five- and ten-year survival rates for patients undergoing curative resection were 36.2 and 14.4%, respectively. The five-year survival of those without nodal metastases was 49.3%, and it was 31.1% in patients with hilar metastases only. The five-year survival of patients with mediastinal metastases who received radiation therapy was 23.1%. Of the 193 patients with squamous cell carcinoma, 43% lived five years free from disease. The five-year survival of patients undergoing resection who had no hilar lymph node metastases was 53%, and it was 47.5% in those with hilar metastases only. The five-year survival in patients with mediastinal metastases who received postoperative irradiation was 34.4%.