Résumé : As concomitant chemoradiotherapy for stage III NSCLC is associated with survival advantage in comparison to a sequential approach, we conducted a phase III randomised study aiming to determine the best sequence and safety of chemotherapy (CT) and chemoradiotherapy (CT-RT), using a regimen with cisplatin (CDDP), gemcitabine (GEM) and vinorelbine (VNR). Unresectable stage III NSCLC patients received CDDP (60 mg/m2), GEM (1 g/m2, days 1 and 8) and VNR (25 mg/m2, days 1 and 8) with reduced dosage of GEM and VNR during radiotherapy (66 Gy). Two cycles of CT with radiotherapy followed by two further cycles of CT alone were administered in arm A or the reverse sequence in arm B. The study was prematurely closed for poor accrual due to administrative problems. Forty-nine eligible patients were randomised. Response rates and median survival times were, respectively 57% (95% CI: 36-78%) and 17 months (95% CI: 9.3-24.6 months) in arm A and 79% (95% CI: 64-94%) and 23.9 months (95% CI: 13.3-34.5 months) in arm B (p > 0.05). Chemotherapy dose-intensity was significantly reduced in arm A. Grade 3-4 oesophagitis occurred in 5 patients. One case of grade 5 radiation pneumonitis was observed. In conclusion, chemoradiotherapy with CDDP, GEM and VNR appears feasible as initial treatment or after induction chemotherapy. Consolidation chemoradiotherapy seems less toxic with a better observed response rates and survival although no valid conclusion can be drawn from the comparison of both arms. © 2008 Elsevier Ireland Ltd. All rights reserved.