To investigate the prognosis of pathological proven T3N0-1M0 non-small cell lung cancer (NSCLC), 73 patients who underwent pulmonary resection between 1975 and 1993 were reviewed. The 5-year survival rate for all patients was 46.3%. The subject included chest wall invasion in 34 (parietal pleura 17, intercostal muscle or ribs 17), invasion to another lobe in 30, main bronchus involvement less than 2 cm distal to the carina in 12, invasion to pericardium in 6 and invasion to diaphragm in 3. The 5-year survival rates was as follows: chest wall invasion 46.7%, invasion to another lobe 51.7%, main bronchus involvement 41.7%, invasion to pericardium and diaphragm 33.3% respectively. The 5-year survival rate was 58.8% when invasion was limited within parietal pleura, whereas 35.3% when invasion extended outside intercostal muscle. Patients invaded within parietal pleura had better prognosis than that of outside intercostal muscle. In conclusion, good outcome would be expected in patients with T3N0-1M0 non-small cell lung cancer when the invasion limited within parietal pleura.