We aimed to describe temporal trends in emergency department (ED) visits of patients with atrial fibrillation (AF) over 12 years. A repeated cross-sectional analysis of ED visits in AF patients using the Korean nationwide claims database between 2006 and 2017 were conducted. We identified AF patients who had ≥1 ED visits. The incidence of ED visits among total AF population, cause of ED visit, and clinical outcomes were evaluated. During 12 years, the annual numbers of AF patients who attended ED at least once a year continuously increased (40,425 to 99,763). However, the annual incidence of ED visits of AF patients was stationary at about 30% because the number of total AF patients also increased during the same period. The most common cause of ED visits was cerebral infarction. Although patients had a higher risk profile over time, the 30-day and 90-day mortality after ED visit decreased over time. ED visits due to ischemic stroke, intracranial hemorrhage, and myocardial infarction decreased, whereas ED visits due to AF, gastrointestinal bleeding, and other major bleeding slightly increased among total AF population over 12 years. A substantial proportion of AF patients attended ED every year, and the annual numbers of AF patients who visited the ED significantly increased over 12 years. Optimized management approaches in a holistic and integrated manner should be provided to reduce ED visits of AF patients.