The prevalence and incidence of atrial fibrillation is increasing along with the geriatric population. Its association with stroke results in significant burden to the patient and to the NHS. Sequelae of atrial fibrillation could be avoided with recognition and appropriate prevention. This article reviews antiplatelet and anticoagulant treatments used for prevention of stroke in patients with atrial fibrillation, with reference to evidence for risk of bleeding, and discusses risk stratification for starting warfarin.