From 1974 through 1983, 125 patients underwent operation at Memorial Sloan-Kettering Cancer Center for non-small cell carcinoma of the lung invading the chest wall. (Excluded are those with superior sulcus tumors or distant metastases at presentation.) Eighty patients were male and 45 were female. Ages ranged from 33 to 88 years (median 60 years). Histologically, the tumors were epidermoid carcinoma in 46%, adenocarcinoma in 46%, and large cell carcinoma in 8%. All patients underwent thoracotomy (pneumonectomy 19, bilobectomy seven, lobectomy 75, wedge resection 10, and no pulmonary resection 14), with an operative mortality of 4%. At thoracotomy, mediastinal lymph node dissection was routinely performed, and the postsurgical stage was T3 N0 M0 in 53%, T3 N1 M0 in 13%, and T3 N2 M0 in 34%. Extrapleural resection was performed in 66 patients. En bloc resection of chest wall and lung was performed in 45 patients with an operative mortality of 2%. Complete resection of tumor was possible in 77 patients (62%). Extension of tumor beyond the parietal pleura significantly decreased resectability. The median survival of 48 patients having incomplete resection was 9 months, despite perioperative interstitial and external radiation. The actuarial 5 year survival rate (Kaplan-Meier) of 77 patients having complete resection was 40%. This percentage was not significantly influenced by the patient's age or sex or by tumor size or histologic type. Lymphatic metastases significantly reduced survival, with a 5 year actuarial survival rate of 56% for patients with T3 N0 M0 disease and 21% for those with T3 N1 M0 or T3 N2 M0 disease (p = 0.005). The extent of tumor invasion of the chest wall appeared to influence survival, but in the absence of lymphatic metastases the difference at 5 years was not significant. Complete resection offers a significant chance for long-term survival in lung cancer directly extending into parietal pleura and chest wall. Extrapleural resection or en bloc chest wall resection can be performed with a low operative mortality and an expected 5 year survival in excess of 50% in the absence of lymphatic metastases.