The role of chemotherapy in the treatment of non-small cell lung cancer (NSCLC) has expanded in recent years, resulting in increased median survival and higher 5-year survival rates in some studies. Few patients with NSCLC can be cured, however, and the median survival time is still modest. Research strategies are aimed at identifying new active single agents, testing their combination in non-cisplatin- and non-carboplatin-containing regimens, and their incorporation into regimens containing more than two drugs, in efforts to improve response and survival and/or reduce toxicity. Several trials of triplet chemotherapy combinations for the treatment of NSCLC have been conducted at the University of Chicago. The three-drug regimen of vinorelbine, paclitaxel, and ifosfamide with granulocyte colony-stimulating factor was evaluated in a phase I trial. Doses of all three drugs were reduced from their standard doses so that toxicity would be manageable, although toxicity was still high. The low response rate (<20%) at the recommended phase II doses led to early closure of this trial. The University of Chicago is also assessing the three-drug combination of carboplatin, paclitaxel, and ifosfamide in patients with stage IIIB and IV NSCLC. The carboplatin and paclitaxel doses are being maintained within their active single-agent range, with the goal of identifying the maximum tolerated dose of ifosfamide when added to this combination. Additional end points include response rates, survival time, and dose-limiting toxicities. This study is ongoing.