Carboplatin, a clinically active analogue of cisplatin, was added to a regimen containing ifosfamide and etoposide, two agents with proven activity in non-small cell lung cancer (NSCLC). From August 1986 until November 1988, 43 consecutive patients (29 men and 14 women), mean age 57 years, performance status of 2 or less, with symptomatic, inoperable NSCLC were accrued and received carboplatin 100 mg/m2 on days 1, 3, and 5, or 300 or 350 mg/m2 on day 1; ifosfamide 1,500 mg/m2 and etoposide 60 or 100 mg/m2 every 4 weeks. Thirty-four patients were previously untreated, nine had been irradiated before, and two had also received previous chemotherapy. So far, 154 courses have been administered; 19 patients have received four or more courses. With the combination of 350 mg/m2 carboplatin and 100 mg/m2 etoposide, myelosuppression was dose-limiting; nephrotoxicity and neurotoxicity did not occur. Evaluation of response after two or four courses in 40 patients showed an objective response in 40%, whereas 30% progressed during therapy. Carboplatin added to etoposide and ifosfamide is a feasible combination that warrants further study in a randomized fashion.