Forty-six patients with non-small cell lung cancer were treated with a combination of cis-platinum 90 mg/m2 i.v., day 1 and VP 16-213 100 mg/m2 i.v. on days 1, 3 and 5. The overall remission rate was 22% (10 out of 46 patients) with a median remission duration of 7 months. Squamous cell and large cell undifferentiated carcinomas responded to the chemotherapy with a remission rate of 27% (7 out of 26 patients) and 22% (3 out of 13 patients). Seven patients with adeno-carcinoma did not respond to chemotherapy. The overall survival was 7 months (1-27+). The survival time for patients entering remission was 11.5 months (7-27+), for those with stable disease 8.5 months (3-27+), and for patients with progressive disease 5 months (1-9). Performance status of less than 80%, a weight loss of more than 10.0 kg in the last three months before starting treatment and a "major" atelectasis (collapse of at least one superior or inferior lobe) adversely influenced prognosis. Only 1 out of 31 patients with one or more poor prognostic factors came into remission. In contrast, 9 out of 15 patients (60%) without poor prognostic factors had a remission. Stage, limited versus extensive disease, and age did not affect the results. Hematologic and renal toxicity of the combination were mild, but poor subjective tolerance (nausea, vomiting, loss of appetite) was prominent.