The initial evaluation of a patient with atrial fibrillation should include a comprehensive review of historical factors, a physical examination and initial investigations. This evaluation has many important purposes, including the development of a therapeutic strategy for symptom relief, the assessment and management of thromboembolic risks, and the identification of underlying etiology. This evaluation should also review management of risk factors for overall cardiovascular morbidity and the treatment of atrial fibrillation. Baseline history, appropriate laboratory tests, and 12-lead electrocardiogram and echocardiography results should be obtained in all patients to identify the potential etiology and other comorbidities, and to stratify for risk of stroke.