To improve patient selection for specialized coagulation testing in the setting of ischemic stroke, the authors sought to identify factors associated with the presence of hypercoagulable states. Of 208 patients with ischemic stroke tested, undetermined stroke subtype was significantly associated with the presence of coagulopathy, but only 60% were treated with warfarin. The frequency of coagulopathy in selected patients with ischemic stroke (5%) is low, and establishing the diagnosis did not uniformly influence treatment.