Concurrent chemoradiotherapy is the recommended therapeutic approach for patients with unresectable stage III non-small cell lung cancer (NSCLC), although surgery offers the chance of cure. With combined-modality therapy with radiation therapy and chemotherapy, the prognosis of stage III NSCLC remains poor. Gefitinib has shown great efficacy in NSCLC patients with EGFR mutations. This study is to studying neoadjuvant gefitinib followed by surgery, followed by adjuvant gefitinib to see how well it works in treating patients with unresectable EGFR mutant stage III NSCLC.