Docetaxel and vinorelbine as single agents and in combination with cisplatin have shown significant activity in advanced non-small cell lung cancer (NSCLC). Significant neutropenia has been observed with the combination of docetaxel/vinorelbine. To gain insight into the potential synergism of this combination, we examined three different sequences of docetaxel 75 and vinorelbine 20 mg/m(2), every 3 weeks, in locally advanced and metastatic NSCLC patients. About 14 patients were evaluable in each schedule: schedule A, docetaxel day 1, vinorelbine days 1 and 6; schedule B, docetaxel day 6, vinorelbine days 1 and 6; schedule C, docetaxel day 1, vinorelbine days 6 and 15. Response rates were: 42.8, 7.1 and 21.4% for schedules A, B and C, respectively (P=0.01, schedule A vs. B). Median survival time was 16, 6.5 and 10.6 months for schedules A, B and C, respectively (P=0.04, schedule A vs. B). Neutropenia was the commonest toxicity; 43% of patients in schedule A and 57% of patients in schedule B had a febrile neutropenia episode. Prophylactic granulocyte-colony stimulating factor (G-CSF) was prescribed in schedule C after the first episode of febrile neutropenia. Non-hematologic toxicities were mild in all three schedules. For future studies, schedule A with lower doses is recommended.