Atrial fibrillation (AF) causes nearly 10% of all ischemic strokes. Long-term oral anticoagulation with warfarin currently is the best treatment for preventing stroke in patients with AF and other stroke risk factors. However, many eligible patients do not receive warfarin, and some patients with AF are unsuitable for this treatment. Recent clinical trials have tested alternatives to long-term warfarin, and some new treatment options have emerged. Nonpharmacologic approaches to stroke prevention in atrial fibrillation also are under development. In addition, new diagnostic modalities may detect paroxysmal AF with more sensitivity, potentially expanding the population to be treated and the potential impact of stroke preventive strategies on the population. This review provides a practical guide to current treatment and diagnostic options.