Primary lung cancer has recently increased progressively in its incidence in Korea. It is clearly evident that surgical resection offers the best offortunity for cure of non-small cell carcinoma. This study was designed to analyse the clinical data of 100 primary non-small cell carcinoma patients who underwent lung resection surgery from January 1992 to July 1995 at the department of Thoracic and Cardiovascular Sugery, Kyungpook National University Hospital. There were 86 males and 14 females(6:1). In the age distribution, the peak incidence was recorded in the seventh decade(43%). The methods of tissue diagnosis were bronchoscopic biopsy in 53 patients(50.5%), percutaneous needle aspiration in 17 patients(16.2%), transbronchial lung biopsy in 11 patients(10.5%), mediastinoscopic biopsy in 2 patients (1.9%), sputum cytology in 2 patients(1.9%), and thoracotomy in 20 patients(19.0%). Fifty-five lobectomies, 22 pneumonectomies, 15 bilobectomies, 2 segmentectomies, 4 sleeve lobectomies, a sleeve pneumonectomy, and a wedge pneumonectomy were performed. Operative mortality occured in 4 cases(sepsis in 2 cases, respiratory failure in 1 case, and acute myocardiac infarction in 1 case). The histologic types of tumor were 67 squamous cell carcinomas, 26 adenocarcinomas, 6 large cell carcinomas, and an adenosquamous cell carcinoma. Eighteen patients with N2 mediastinal lymph node metastases had 8 squamous cell carcinomas(11.9%), 9 adenocarcinomas(34.6%), and a large cell carcinoma(16.7%). The primary tumors in these patients were in the right upper lobe in 4 patients, the right middle and lower lobe in 9 patients, the left upper lobe in 3 patients, and the left lower lobe in 2 patients. With regard to pathologic stages, 45 patients had stage I disease; 13 patients, stage II; 36 patients, stage IIIa; 5 patients, stage IIIb; and 1 patient, stage IV. The overall actuarial survival rate was 77.5% at 12 months, 56.1% at 24 months and 43.7% at 43 months. The actuarial survival rates at 43 months were 81.3% in Stage I, 20.8% in Stage II, 27.9% in Stage IIIa, 25.0% in Stage IIIb and 33.3% in Stage IV. These facts suggest that early detection and surgical resection are recommended for favorable postoperative survival in non-small cell lung cancer.