Purpose: Our objective was to determine the activity in terms of re sponse rate, surgical resectability, and the tolerability of the new three-drug combination gemcitabine-cisplatin-paclitaxel (GCP) in unresectabte stage IIIA(N2) and IIIB non-small cell lung cancer (NSCLC). Patient and methods: Forty-two chemo-naive patients with stage IIIA(N2)-IIIB NSCLC, median age of 59 years, Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, and the ability to tolerate pneumectomy, received gemcitabine (Gem) 1000mg/m(2) IV days 1 and 8, cisplatin mg/m(2) Mg/M-2 (CDDP) 50 IV days 1 and 8, paclitaxel 125 1 h infusion IV days 1 and 8, every 21 days for 3 cycles. After induction chemotherapy, patients were evaluated for surgery or definitive radiotherapy. Results: Grade 3-4 neutropenia was the main hematologic toxicity, occurring in 28% of patients. Grade 3-4 thrombocytopenia was observed in only 11 % of cases. No neutropenic fever or bleeding episodes were recorded. Severe non-hematologic toxicity was uncommon. Thirty (71%, 95% Cl: 57.2-84.7%) of the 42 eligible patients had objective responses (1 complete and 29 partial responses). After induction chemotherapy, 21 patients (50%) went to surgery. Complete resection was obtained in 16 patients (38%). Viable tumor was present in 18 of 21 resection specimens. In three cases only necrotic tumor cells were identified, for a pathological complete response of 7%. With a median follow-up of 13.9 months, median time to progression was 17.4 months, median survival 21.7 months and estimated 1-year survival 92%. Conclusions: GCP combination is active and well tolerated in locally-advanced, non-resectable NSCLC. The activity profile, in terms of response and surgical resection rate, is comparable to that obtained with standard doublets. (C) 2003 Elsevier Ireland Ltd. All rights reserved.