We conducted a phase I/II trial to determine the maximum tolerated dose (MTD) and the efficacy of prolonged infusion of cisplatin and oral etoposide in the treatment of advanced non-small cell lung cancer (NSCLC). Cisplatin was given via an infuser in escalating doses of 5, 6.5, 8, 9 and 10 mg/m2/day for 14 days along with etoposide at a fixed dose of 50 mg/m2/day orally followed by a 2-week rest period. All patients had stage IIIB or IV NSCLC. A cisplatin dose of 8 mg/m2/day was determined as the MTD. In the 13 patients treated at this dose level, grade III and IV toxicities were mainly hematologic including neutropenia (n=5), febrile neutropenia (n=4), thrombocytopenia (n=3) and anemia (n=6). Grade III/IV renal toxicity occurred in one patient. There were no treatment-related deaths. One patient had a partial response and three patients had stable disease. Thus, although the described regimen of cisplatin/etoposide is reasonably well tolerated, it does not appear to be better than the same combination administered over a shorter duration, in spite of a cumulative dose of 112 mg/ m2of cisplatin and 700 mg/ m2of etoposide per cycle.