Abstract Background Old age is an important factor that could affect the treatment of early-stage lung cancer. In this study, we evaluated the treatment patterns and outcomes of patients over the age of 80 years who had been diagnosed with early-stage lung cancer in real-world practice. Methods Elderly patients who were diagnosed with early-stage lung cancer between 2008 and 2016 were identified using claims data provided by the Health Insurance Review and Assessment Service. The proportion of patients who underwent surgical resection or stereotactic body radiation therapy (SBRT), practice pattern trends, and overall survival (OS) were analyzed from the population-based data. Results Over 9 years, 1,684 patients underwent surgical resection (74.9%) or SBRT (25.1%) as a localized treatment. From 2008 to 2016, the treatment modality changed: the percentage of patients who underwent surgical resection decreased from 90.6 to 71.4%, and those who underwent SBRT increased from 9.4 to 28.6%. The percentage of patients treated with SBRT increased over time (p