Aim: A prospective study for stage IIIA-B non-small cell lung cancer (NSCLC), with three-times daily (3td) radiotherapy (RT), after induction chemotherapy (iCT), with or without surgery. Patients and Methods: Induction cisplatin and gemcitabine chemotherapy was delivered. Surgery and postoperative (post-op) radiotherapy were planned for responsive stage IIIA patients; definitive irradiation was performed in unresectable III A and IIIB patients. Doses of 54.4 and 64.6 Gy were delivered for the post-op and definitive treatments, respectively. Results: Out of 52 patients (pts), 37 received 3tdRT as definitive (18 pts) or post-op treatment (19 pts). Overall, the failures were similar between post-op and definitive 3tdRT (78.9% vs. 77.8%). In the post-op treatment, metastases and local failures were 52.6% and 10.5%, respectively and in the definitive radiotherapy, the incidence was similar (local 33.3% vs. systemic 44.4%). The five-year overall survival (OS) was 25% for the post-op and 21% for the definitive patients (p=0.87). Conclusion: Three-times daily postoperative radiotherapy did not improve the outcome in NSCLC, but for unresectable patients, this approach may have a role in selected cases