Atrial fibrillation is a common disease of the elderly, conferring considerable morbidity and mortality related to cardiovascular effects and thromboembolic risks. Anticoagulation, antiarrhythmic medications, and rate control are the cornerstone of contemporary management, whereas ablation and evolving surgical techniques continue to play important secondary roles. Growing evidence shows that atrial fibrillation is also a risk factor for significant cognitive decline through a multitude of pathways, further contributing to morbidity and mortality. At the same time, cognitive decline associated with cryptogenic strokes may be the first clue to previously undiagnosed atrial fibrillation. These overlapping associations support the concept of cognitive screening and rhythm monitoring in these populations. New research suggests modulating effects of currently accepted treatments for atrial fibrillation on cognition; however, there remains the need for large multicenter studies to examine the effects of novel oral anticoagulants, rhythm and rate control, and left atrial appendage occlusion on long-term cognitive function.