Forty-six patients with metastatic non-small-cell lung cancer (NSCLC) were treated with a combination of high-dose cisplatin, etoposide, and mitomycin. Thirty-four patients (74%) had a performance status of 1, and 39 patients (85%) had adenocarcinoma. Of the 42 patients evaluable for response and toxicity, four achieved a partial response (10%); no patient achieved a complete response. Seven patients who had received prior chemotherapy showed no major response. The median survival of all 42 patients was 23 weeks. Myelosuppression was the major dose-limiting toxicity for this regimen, and 12 of 46 patients (26%) developed neutropenic fever requiring hospitalization and parenteral antibiotics. Of the 12 patients with severe neutropenic fever, one patient died because of toxicity. Nonhematologic toxicities, including azotemia, peripheral neuropathy, nausea, vomiting, and hearing loss were transient and modest. We conclude that high-dose cisplatin combined with etoposide and mitomycin is a relatively toxic regimen with a low response rate. Further evaluation of the combination as given in this trial is not warranted.