We reviewed 139 cases of thoracotomy for lung cancer, performed during a 7 1/2-year period. Patients were divided into two groups based on age: a younger group (less than 70 years old) and an elderly group (greater than or equal to 70 years old). Among all cases of lung cancer diagnosed during the study period, the percentage of patients undergoing thoracotomy in both groups was comparable. Comparison of baseline features of the two groups revealed no statistical difference in the distribution of sex, smoking history, arterial blood gas values, degree of airflow obstruction, cell type, stage of cancer, or subsequent therapy. Potentially serious medical problems were more frequent in the elderly group, whereas the younger group had significantly higher values for several pulmonary function parameters and underwent a significantly higher proportion of pneumonectomies. Although operative mortality in the elderly group was greater (9.4% vs 4.0%; 95% confidence intervals, 3.5%, 19.3% vs 0.8%, 11.2%), [corrected] further analysis of outcomes revealed no statistically significant difference in the postoperative complications, postoperative hospital stay, or actuarial survival. We conclude that advanced age does not adversely affect prognosis following thoracotomy for lung cancer. Therefore, elderly patients with reasonable cardiopulmonary function should not be denied potentially curative pulmonary resection because of concern for age-related complications.