For more than two decades, anticoagulant and antiplatelet agents have been used routinely to prevent and treat ischemic stroke. Although recent clinical trials have shown that such treatment can be helpful in certain cases, antithrombotic therapy currently remains of unproven benefit in many clinical settings of cerebrovascular disease. Although the absence of data confirming clinical efficacy has generated uncertainty and hesitancy in some clinicians, the lingering conviction that antithrombotic therapy is efficacious has led others to continue a policy of routine and active therapeutic intervention. A critical analysis of the literature on antithrombotic therapy and cerebrovascular disease suggests that many acceptable management options lie between the extremes of therapeutic nihilism and "routine" intervention.