Nine patients with stage IIIB non-small cell lung cancer were entered into a phase II trial designed to determine the feasibility of giving a combination of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) plus cisplatin concurrent with thoracic radiation. Paclitaxel was given as a 24-hour infusion (135 mg/m2) followed by cisplatin (75 mg/m2) every 4 weeks, for a total of four cycles. Thoracic radiation was given concurrently with the first two cycles of chemotherapy, for a total dose of 64.8 Gy over 6 weeks. Neutropenia and esophagitis were the most common toxicities, with 66% of patients experiencing grade 3 or 4 neutropenia and 55% experiencing grade 3 or 4 esophagitis. Grade 3 pulmonary toxicity developed in 33% of patients. All patients were able to receive the full dose of radiation, although half of the patients required some modification of the chemotherapy regimen. There was one complete response and four partial responses, yielding a 56% overall response rate. This study demonstrates that it is feasible to treat patients with stage IIIB non-small cell lung cancer with paclitaxel/cisplatin plus concurrent thoracic radiation, with a degree of toxicity comparable with that associated with a degree of toxicity comparable with that associated with other concurrent combined-modality regimens for this disease.