The synergistic effects of new generation chemotherapeutics when combined with cisplatin have encouraged the development of new triplet combination regimens in the treatment of advanced non-small cell lung cancer (NSCLC). The aim of this study was to evaluate the feasibility of triplet chemotherapy using weekly cisplatin-gemcitabine-docetaxel (CGD) for patients with chemotherapy-naive NSCLC. Twenty-seven patients with stage IIIB/IV disease and performance status of 0 to 2 were included in this prospective trial. A combination of gemcitabine 750 mg/m(2), cisplatin 25 mg/m(2) and docetaxel 25 mg/m(2) was administered on days 1, 8 and 15, with cycles repeated every 3 weeks. Leucopenia and/or neutropenia and to a lesser extent thrombocytopenia were the main dose-limiting toxicities. Grade III-IV neutropenia and thrombocytopenia occurred in 26 and 7% of the patients, respectively. Only one patient developed febrile neutropenia. Dose reductions were required in 26% of patients, delays in 44% of patients and early treatment discontinuation in 15% of patients. The overall response rate was 52% and all of them experienced a partial response. The median progression-free (PFS) and overall survival (OS) times were 6 and 13 months, respectively. The one-year survival rate was 46%. In conclusion, weekly administration of CGD is an active first-line therapy with acceptable toxicity in advanced NSCLC patients.