A phase II study of a combination therapy with vinorelbine (Navelbine) plus cisplatin was performed using 27 patients with advanced non-small cell lung cancer, to evaluate the efficacy and safety of this therapy. Patients were treated, at 3-week intervals, with two or more courses of a regimen consisting of vinorelbine 25 mg/m2 (days 1, 8) and cisplatin 80 mg/m2 (day 1). The response rate was 48.1% (13/27) (95% confidence interval: 28.7-68.1%). The median number of treatment courses was 2.6. The major toxicity was hematological: 74% of patients had neutropenia of grade 3 or higher that subsided rapidly upon administration of a granulocyte-colony stimulating factor. Non-hematological toxicities were mild, of grade 2 or less: the main symptom was nausea/vomiting (62%), although constipation, eruption, anorexia, peripheral nerve disorders, diarrhea, fever, and other conditions were also observed. In conclusion, the high response rate and good tolerance to this combination therapy warrants further study.