Mediastinal lymph node involvement [N2 disease] is generally accepted as an important factor influencing the outcome of patients with lung cancer.The long-term survival rates of completely resected patients with N2 disease are frequently reported from 15% to 30%.To improve the management and the outcome of patients with resectable N2 disease, we analyzed the survival rates and the prognostic factors for resected N2 lung cancer. Between August 1989 and September 1993, we experienced 27 patients with N2 disease of 115 surgically treated lung cancer at the Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, Ulsan University Medical School. Of these 27 N2 disease 4 had only an exploratory thoracotomy, and 23 underwent pulmonary resection by pneumonectomy[15], bilobectomy[3], lobectomy[4] and sleeve lobectomy[1].All of resected 23 patients received postoperative adjuvant chemotherapy[3], radiotherapy[2] or combined chemo-radiotherapy[18].Complete follow-up was obtained in 23 patients and median survival was 22 months and overall 1-year and 2-year survival rates by Kaplan-Meir method were 65 % and 45 %, respectively. Survival differences according to histology, tumor location, number of positive nodal station and operative method were not significant, statistically. Conclusively, we think that in resectable N2 lung cancer, complete tumor resection and mediastinal lymph node dissection, and postoperative adjuvant therapy should be done to improve the survival.