Between 2/87 and 10/89, 83 patients (pts) with previously untreated NSCLC were assigned at random to receive either the PI regimen (cisplatin 80 mg/m2 dl and ifosfamide 2 g/m2 d 1, 2, 3, q 3-4 wks) or the PV regimen (cisplatin 80 mg/m2 d 1 and vindesine 3 mg/m2 d 1, 8, 15, q 3-4 wks). Three pts (2 PI regimen, 1 PV regimen) were ineligible for the study and 13 pts (7 PI regimen, 6 PV regimen) did not complete it. Thirty-three PI regimen pts and 34 PV regimen pts completed 2 or more cycles of the treatment and were evaluated. Patient characteristics were almost identical in both groups in terms of sex, age, pathological types, stage, performance status and number of chemotherapy cycles. For the PI regimen, there were 1 C.R. and 6 P.R., and the response rate was 21.2% (7/33). In the PV regimen, there were 11 P.R., and the response rate was 32.4% (11/34). The median survival time (MST) for PI regimen was 29 weeks (range 12-156 wks) and for PV regimen 40 weeks (range 8-138 wks). The difference in the survival curves for the 2 regimens was not statistically significant. Toxicities for the 2 regimens were similar except for greater leukopenia and one treatment-related death due to renal toxicity on PI regimen. These results suggest that PI regimen is not superior to PV regimen in the treatment of NSCLC.