This study is to evaluate and report the prognostic factors of N2 positive stage IIIA non-small cell lung cancer (NSCLC) treated with concurrent radiochemotherapy (CRCT) and surgery. CRCT and surgery were planned in 66 patients with stage IIIA NSCLC, and 46 evaluable patients were analyzed. Thoracic radiation therapy (TRT) dose was 45 Gy over 5 weeks, chemotherapy consisted of two cycles of intravenous cisplatin (100mg/m(2), on days 1 and 29 of TRT) and oral etoposide (50mg/m(2)/day, on days 1-14 and 29-42 of TRT), and surgery was performed in 4 weeks following CRCT completion. With the median follow up duration of 23 (range 5-74) months, the overall survival, disease-free survival, and local control rates at 5 years in all patients were 27%, 24% and 90%, respectively. The overall survival and disease-free survival rates at 5 years in the patients who achieved ypN0 stage and ypN1/2 stages were 47% and 0% (p=0.008), and 42% and 7% (p=0.01), respectively. The corresponding figures in those with initial "bulky" N2 disease and "mediastinoscopic" N2 disease were 31% and 19% (p=0.98), and 23% and 26% (p=0.68), respectively. Following CRCT and surgery, achieving ypN0 stage turned out to be a significantly favorable indicator, while the initial mediastinal lymph node extent did not, with respect to overall survival and disease-free survival.