A phase II study was conducted to determine the efficacy and the safety of docetaxel combined with vinorelbine as first-line chemotherapy in patients with metastatic or unresectable non-small cell lung cancer (NSCLC). 39 patients, median age 54 years (range: 35-69), with stage IIIB (5 patients; 13%) or IV (34 patients; 87%) NSCLC were treated with 75 mg/m(2) docetaxel given intravenously (i. v.) over 1 h on day 1 and with 20 mg/m(2) vinorelbine given i.v. over 15 to 30 min on days 1 and 5. Cycles were repeated every 3 weeks. 9 of the 39 patients had a partial response (overall response rate 23.1%, 95% confidence interval (CI): 11.1-39.3%) with a median duration of response of 20 weeks (95% CI; 17-30). The median survival was 40 weeks (95% CI: 21-49 weeks) with a 1-year survival rate of 31% in the intent-to-treat population. Neutropenia grade IV occurred in 33 patients (92%). 16 patients (41%) experienced febrile neutropenia with a concomitant stomatitis in 9 patients (23%). One patient died due to febrile neutropenia associated with a grade 4 stomatitis and 1 patient due to a septicaemia concomitant with a grade 4 neutropenia. Although the combination of docetaxel and vinorelbine is feasible, the efficacy does not seem to be improved compared with single-agent docetaxel or vinorelbine and the rate of febrile neutropenia is unacceptable in this population with incurable disease. Therefore, different doses and/or schedules are to be explored.