OBJECTIVES: I. Determine the maximum tolerated dose and dose limiting toxicity of gemcitabine and paclitaxel in combination with radiotherapy in patients with locally advanced stage IIIA or IIIB non-small cell lung cancer. II. Assess response rate, duration of response, disease free survival and failure in this patient population on this regimen. III. Determine the pharmacokinetics of gemcitabine and paclitaxel during the chemoradiotherapy phase.