Prognosis of Stage III NSCLC remains dismal, particularly when mediastinal nodal involvement is present. In order to improve local control and to reduce early distant failures, we have treated Stage III patients with concurrent chemoradiotherapy since 1989. From September 1989 to February 1994, 140 patients were treated with concurrent chemoradiotherapy. Among these, 24 initially inoperable patients became operable after induction chemoradiotherapy. Characteristics: median age 51 years (35-70); squamous: 45.8%; non squamous: 41.7%; median tumor size: 8 cm; T3 (79.2%); T4a (12.5%); N2 (62.5%) and N3 (8.3%). Preoperative radiotherapy was delivered at a dose of 45 Gy (25 f) over 5 weeks to the mediastinum. Concurrent chemotherapy was continuous infusion cisplatin (n = 10) or cisplatin plus etoposide (n = 14). Five weeks later, radical surgery was carried out (lobectomy n = 14, pneumonectomy n = 10), followed by additional chemotherapy (n = 12) and/or radiotherapy (n = 6), according to histological response. Pathological CR rate was 29.2%. Grade III toxicities were digestive (12.5%), hematologic (8.3%) and infectious (4.2%). Three patients had severe non-lethal postoperative complications with one hemorrhage and two pneumothorax (12.5%). With a median follow-up of 41 months, overall survival at 2 and 5 years was 77.5%, and 72%, respectively. Actuarial local control at 5 years was 82.4%. Nine patients presented with distant metastases, including six with isolated brain metastases. This preoperative chemoradiotherapy regimen appears feasible without overwhelming toxicity and with an acceptable rate of postoperative complications. Despite a significant incidence of isolated brain metastases (25%), 5-year survival is highly encouraging since and appears substantially better than primary surgery.