Twenty-seven patients (25 males and 2 females) with histologically confirmed, unresectable, or metastatic non-small cell lung cancer were entered on a combination chemotherapy protocol including cisplatinum and vinblastine sulfate (DDP)(VLB). Patients had to have measurable disease as defined by the presence of two clearly measurable perpendicular diameters, be untreated with either chemotherapy or radiation therapy, and give informed consent to be eligible for study entry. The median age was 57 yr and the median performance status was 70 (Karnofsky scale); 10 patients had epidermoid carcinoma, 9 adenocarcinoma, 4 large cell carcinoma, and 4 undifferentiated carcinoma. All patients had intrathoracic disease, 12 also had extrathoracic lymph node involvement, 8 bone involvement, 2 liver metastasis, and 2 central nervous system metastasis prior to beginning chemotherapy; 9 patients had involvement of one site, 12 of two sites, 5 of three sites, and 1 of four sites. Cisplatinum was given as a short intravenous infusion of 120 mg/m2 on days 1 and 28, and then every 6 wk. Vinblastine was administered as an intravenous injection of 8 mg/m2 on days 1, 14, and 28, and then every 3 wk. Patients were evaluated prior to each course of cisplatinum. If progression occurred, therapy was discontinued. If stabilization or response was noted, then therapy was continued until intolerable toxicity or progression supervened. Every patient entered is considered evaluable for toxicity and response. There were no complete remissions; 14 patients achieved a partial response, 3 had a minimal response, 5 had stabilization of their disease, 1 had disease progression, and 4 are considered to have had drug deaths. Responses were seen after the first cisplatinum course in 13 patients and after the second in 1. Toxicities seen were universal nausea and vomiting; elevation of creatinine occurred in 6 patients, ranging from 2.1 to 14.6 mg/dl, and was clinically significant in 2 patients. Myelosuppression, with a leukocyte nadir of less than 3.0 X 10(9)l in 10 cases and platelet nadir of less than 100.0 X 10(9)l was seen in 5 cases and partial hearing deficit occurred in 2 patients. Median survival was 22 wk for the whole group (24 wk for the whole group if the 4 early drug deaths are excluded). Median survival was 26 wk for responding patients and 13 wk for nonresponding patients (remains the same if the early deaths are excluded from the latter group).(ABSTRACT TRUNCATED AT 400 WORDS)