The study will evaluate the incorporation of ZD1839 with concurrent CP and TCRT to a dose of 74 Gy following 2 cycles of induction CIP. The primary objective will be to define the toxicity profile of this approach. With amendment 2, patients will no longer receive maintenance ZD1839. Given the data generated on LCCC 9603 and 2001, this "hybrid" platform of induction CIP followed by concurrent TCRT (74 Gy) and CP seems appropriate for incorporation of ZD1839 because of the general tolerance of this therapy in good PS, unresectable, Stage III NSCLC subjects. Given that esophagitis is the primary toxicity seen with this approach, stopping rules will be in place for excessive esophageal toxicity.