Introduction: The purpose of this study was to evaluate the treatment outcomes of sterotactic body radiotherapy (SBRT) for early stage of non-small cell lung cancer (NSCLC). Methods: From January 2011 to June 2012, 19 patients with NSCLC were treated with SBRT by using Novalis Tx at our institute. The patients ages were 64-86 years (median: 76). Nine of the patients were inoperable because of poor cardiac or pulmonary function (7) or other malignancy (2). Others (9/19) refused operation due to old age. The stages of lung cancer were IA in 11, IB in 7, IIA in 1. SBRT was given using Novalis Tx with 48-60 GY in 4 or 5 fraction. Median follow up time was 414 days (84-611 days). Results: The response rate (RR) at 3 months was partial response (PR) in 14 patients, stable disease (SD) in 3 and progressive disease (PD) in 2, whereas the RR at the time of the last follow up was PR in 13 patients, SD in 3, PD in 3. Three patients with PD showed mediastinal lymph node metastasis (3) and concurrent lung metastasis (1) and showed only 1 local progression of the lesion targeted by SBRT. Total local control rate was 99%. Total 4 patients died after SBRT due to lung cancer progression( 1) or pneumonia(2) or unknown cause (1). The overall and disease-specific survival rate at 1 year was 79% and 99% respectively. No Grade 2 or higher SBRT-related toxicities were observed. Conclusion: SBRT using a Novalis Tx was proven to be an effective treatment modality for early stage NSCLC based on high local control rate without any significant complications. However, further long term follow up is needed.