7556 Background: Standard treatment of resectable N2 disease is not yet established. To gain insights on significance of preoperative chemoradiotherapy, we tried to evaluate feasibility and efficacy of induction chemotherapy with or without radiotherapy followed by surgery in patients with stage IIIA NSCLC with mediastinal lymph node metastases. Methods: Patients with histologically proven N2 disease were randomized either to receive induction chemotherapy (taxotere 60 mg/m2 and carboplatin AUC 5x2 cycles) with concurrent radiation therapy of 40Gy/20fr (CRS group) or without it (CS group). Patients subsequently underwent pulmonary resection if the tumor was judged resectable. Original sample size was 180 to detect a 20% of survival difference (2 sided P=0.05) with a power of 0.8. The primary endpoint was overall survival. Results: Between Jan. 2001 and Dec 2005, 60 patients were randomized Because of poor accrual of the patients, the study was prematurely terminated. Two patients assigned to CRS group were ineligible due to staging misconducts. Median age was 57 years (range 34–70 years), and 66% were male. Two groups were well balanced with regard to age, gender, histology, and operative procedures. Induction therapy was well tolerated, and there was no treatment related death. Grade 3 and 4 neutropenia occurred in 74 and 89%, respectively. Objective response rate was 25% for the both groups. Surgical resection was performed in 86% and 89%of the patients in CS and CRS groups, respectively. There have been 37 deaths to date. Event free survival at 3 year was 18% and 32% for patients in CS and CRS group, respectively (HR=0.64; 95% CI: 0.36–1.17, P=0.15). Overall survival at 3 year was 44.4 %. and 52.7% (HR=0.84; 95% CI: 0.44–1.62, P=0.62), respectively. Conclusions: Because of small sample size, there was no statistically significant difference. However, our study suggested that addition of radiotherapy to induction chemotherapy could potentially prolong survival of NSCLC patients with N2 disease. [Table: see text]