Paclitaxel (Taxol; Bristol-Myers Squibb) is one of the most active single agents for non-small cell lung cancer (NSCLC), and ideal in combination with radiation therapy. We designed a phase II study to determine the efficacy and toxicity of continuous hyperfractionated accelerated radiotherapy (CHART) and concurrent weekly Paclitaxel (T) in good performance status patients with unresectable stage III A and B NSCLC. T (60 mg/m2) was given as a 3-h infusion on days 1, 8, 15, 22, 29 and 36; CHART was started on day 15 with 150 cGy/fraction given three times a day for a total dose of 54 Gy in 12 days with no weekend break. Twenty patients were evaluable for acute toxicity. The major acute toxicities were esophagitis and pulmonary toxicity; 70% of the patients experienced grade 2-3 esophagitis and 50% experienced grade > or = 3 pulmonary toxicity. Grade 3 anemia developed in only one patient. Of the 17 patients evaluable for late toxicity, 12% of the patients had grade 3 pulmonary toxicity, one patient developed grade 4 esophagitis. Nineteen patients were evaluable response. The overall response rate was 84% (95% confidence interval, 60-97). CHART with concurrent weekly T seems to be an effective regimen, but tolerability needs to be documented with a larger number of patients and longer follow-up.