A phase II trial was performed to evaluate the efficacy and toxicity of the novel combination of vinorelbine and paclitaxel as first-line chemotherapy in patients with stages IIIB and IV non-small-cell lung cancer. From January 1997 to September 1999, 34 patients (9 stage IIIB and 25 stage IV) received a regimen consisting of the following: vinorelbine 30 mg/m2 20 minutes intravenous (i.v.) infusion, days 1 and 8; and paclitaxel 135 mg/m2 3-hour i.v. (starting 1 hour after vinorelbine) on day 1. Cycles were repeated every 28 days until progression of disease or unacceptable toxicity development. The median age was 57 years (range 41-70 years); median performance status was 1. Histology was as follows: squamous cell in 24 (71%), large cell in 1 (3%), and adenocarcinoma in 9 (26%). All patients are evaluable for toxicity, whereas 30 are evaluable for response (4 patients refused treatment). Objective response was recorded in 4 of 30 patients (13%, 95% CI 1-25%). No complete response was observed. Partial response was recorded in 4 patients (13%), no change in 10 patients (34%), and progressive disease in 16 patients (53%). The median time to treatment failure was 4 months and median survival was 9 months. The limiting toxicity was myelosuppression: leukopenia in 23 patients (68%), whereas neutropenia was observed in 25 patients (78%). Peripheral neurotoxicity developed in 14 patients (41%) (without G3 or G4 episodes), and constipation (G1-G2: 10 patients), myalgia (G1-G2: 11 patients), diarrhea (G1-G2: 7 patients), and stomatitis were observed in 7 patients. Vinorelbine-paclitaxel combination showed only modest activity against locoregionally advanced or metastatic NSCLC.