The factors affecting survival were evaluated in patients aged ≥ 70 years with non-small cell lung cancer (NSCLC) treated with definitive radiotherapy (RT). Between January 1996 and April 2012, 52 patients were treated. The median age was 73 (range: 70-80), 73% and 75% of patients with stage III according to AJCC 2002 and 2010, respectively. Radiotherapy was performed median 6160 cGy (range: 3600-6660) and chemotherapy (CHE) were given 75% of the patients as neoadjuvant, concurrent or adjuvant. Statistical analyses were calculated with Kaplan-Meier and Cox regression methods. Median follow-up was 12.5 months (range: 2.5-103). Median overall (OS), disease-free (DFS) and locoregional-progression-free (LRPFS) survival were 22 (95% CI 12-31), 18.5 (95% CI 7-29) and 25 months (95% CI 15-34), respectively. Two-year OS, DFS and LRPFS rates were 50%, 47% and 52%, respectively. Acute ≥ Grade 3 esophagitis and neutropenia were seen 6% and 10% of patients. Whereas the mortality associated with CHE were seen of 5 (10%) patients, RT-related death was not observed. In univariate analysis; AJCC 2002 stage I-II (72.5 vs 20 months, p = 0.05), RT dose ≥ 60 Gy (27.5 vs 12.5 months, p = 0.01), RT duration >49 days (31 vs 11 months, p < 0.001) for OS and RT dose ≥ 60 Gy (25 vs 11 months, p= 0.02), RT duration >49 days (26.5 vs 10.5 months, p <0.001) neoadjuvant CHE ≤ 3 cycles (mean 58 vs 19 months, p = 0.03), complete response (72.5 vs 18.5 months, p = 0.03), ≥ 4 cycles of CHE (25 vs 11 months, p = 0.05) for DFS were significant. In multivariate analysis, RT duration > 49 days were found a positive impact on OS (HR: 3.235, 95% CI: 1:25 to 8:32 p = 0.01). Definitive and palliative RT plays an important role in elderly lung cancer patients have multiple co-morbidities with limited treatment options. In our study, elderly patients with NCSLC can be given ≥ 60 Gy without complications and was seen positively impact on survival.