Platinum compounds and vinorelbine have been demonstrated to be active in non-small-cell lung cancer (NSCLC). The aims of the study were to assess tolerability and feasibility of increasing doses of carboplatin (level 1: 300 mg/ m2 on day 1, level 2: 350 mg/m2 on day 1, level 3: 400 mg/m2 on day 1) in combination with a fixed dose of vinorelbine (25 mg/m2 on days 1 and 8) in advanced NSCLC. Forty-two patients entered the study and were evaluable for toxicity and response. The patients were not treated using systemic chemotherapy, had TNM stage IIIB-IV, performance status ECOG 0-2, and their median age was 62 (range 41-70) years. The number of patients evaluable for each dose level was 14. A total of 138 (median 3) courses was administered. Nonhematologic side effects included grade I-II mucositis (9%), neurotoxicity (6%), and infections (4%). Myelotoxicity was manageable and generally of short duration, with 19% of the patients having grade III-IV neutropenia. No significant difference was observed for the three treatment groups. No drug-related death was observed. An objective remission was observed in 10 patients (24% response rate; 95% confidence interval 12-39%), with 5 responses in 14 patients treated with the 400-mg/m2 dose. In conclusion, the combination of carboplatin at a dose of 400 mg/m2 on day 1 and vinorelbine at a dose of 25 mg/m2 on days 1 and 8 can be safely administered as first-line cytotoxic therapy in advanced NSCLC and warrants further evaluation.