Objectives: Although atrial fibrillation (AF) is one of the most common rhythm disorders observed in clinical practice, a multicenter epidemiological study has not been conducted in our country. This study aimed to assess our clinical approach to AF based upon the records of the first multicenter prospective Atrial Fibrillation in Turkey: Epidemiologic Registry (AFTER) study. Study design: Taking into consideration the distribution of the population in our country, 2242 consecutive patients with at least one AF attack determined by electrocardiographic examination in 17 different tertiary health care centers were included in the study. Inpatients and patients that were admitted to emergency departments were excluded from the study. Epidemiological data of the patients and the treatment administered were assessed. Results: The mean age of the patients was determined as 66.8±12.3 years with female patients representing 60% of the study population. While the most common AF type in the Turkish population was non-valvular AF (78%), persistent/permanent AF was determined in 81% of all patients. Hypertension (%67) was the most common comorbidity in patients with AF. While a stroke or transient ischemic attack or history of systemic thromboembolism was detected in 15.3% of the patients, bleeding history was recorded in 11.2%. Also, 50% of the patients were on warfarin treatment and 53% were on aspirin treatment at the time of the study. The effective INR level was detected in 41.3% of the patients. The most frequent cause of not receiving anticoagulant therapy was physician neglect. Conclusion: These results demonstrate the necessity for improved quality of physician care of patients with AF, especially with regards to antithrombotic therapy. © 2013 Turkish Society of Cardiology.