The aim of this study is to evaluate the present status of stroke prevention strategies in patients with non-valvular atrial fibrillation (NVAF). Vitamin K antagonists (VKAs) have been the only available oral anticoagulant therapy for decades. Recently novel oral anticoagulants have emerged as an alternative for VKAs. This study is planned to evaluate the epidemiological characteristics, thromboembolic and bleeding risks, stroke prevention strategies and appropriateness of oral anticoagulant use in NVAF patients. Time in therapeutic range (TTR) is going to be calculated as the percent of visits in range (2-3) for warfarin patients. This is a national multicenter observational study in which Turkey is divided into seven regions. A proportional number of patients to the population of every region is planned to be included.