Traditionally, patients with stage IIIB non small cell lung cancer (NSCLC) have been con-sidered Inoperable due to the short-term survival rate of this disease. However, some recent papers have reported good surgical treatment results for T4 lesions in stage IIIB NSCLC. This study reports the results of stage IIIB NSCLC patients who underwent surgical treatment at our institute. Material and Method: This study includes 109 patients who were diagnosed with pathological stage IIIA lung cancer and 59 patients who were diagnosed with pathological stage IIIB at our institute between 1994 to December 2001. Patients who underwent neo-adjuvant chemotherapy and radiation therapy were excluded from this study. According to the TNM classification, 13 patients from stage IIIA were classified into T3N1, 12 into T1N2, 73 into T2N2 and 11 into T3N2. Stage IIIB patients consisted of 26 patients with T4N0, 18 with T4Nl, 14 with T4N2, and 1 with T4N3. Result: The 30-day mortality for stage IIIA and IIIB were 4.58% and 5.08% respectively. The overall survival rate at the 1st, 2nd, 3rd, and 5th year were 69.1%, 53.7%, 41.6%, and 30.7% respectively in stage IIIA and 68.8%, 55.6%, 42.9%, and 35.9% respectively in stage IIIB. Patients with satellite nodules in the same lobe & no Iymph node involvement had a survival rate of 53.9% in 3 years compared with 15.2% in patients with satellite nodules in the same lobe with Iymph node involvement. Conclusion: Surgical treatment is recommended for selected stage IIIB NSCLC patients (pathological N0 stage & completely resectable patients), particularly for patients with satellite nodules in the same lobe & no lymph node involvement.