Fifteen patients with advanced non-small cell lung cancer, already treated with first-line chemotherapy, entered a protocol of palliative second-line treatment with the hemysynthetic vinca alkaloid vinorelbine (25 mg/sm weekly for two months). No patient obtained an objective response and the trial was stopped. Toxicity was not as mild as expected, with one treatment-related death due to leukopenia. It is concluded that single-agent vinorelbine, although effective as front-line chemotherapy for non-small cell lung cancer patients, is probably not suitable for palliative treatment of pretreated patients.