Antiphospholipid antibodies are a marker for an increased risk of thrombosis, including stroke and transient ischemic attacks. Prior studies suggest that patients with these antibodies and thrombosis may be at increased risk for recurrent thrombotic events. We prospectively evaluated 75 patients with antiphospholipid antibodies and cerebral or ocular ischemia for recurrence of thrombosis. Twenty-six patients (35%) experienced a recurrent stroke or transient ischemic attack, with a mean time to recurrence of 1.18 years. Hypertension significantly increased the risk of a recurrent transient ischemic attack. Patients with coronary artery disease were three times as likely as those without to have a recurrent stroke or transient ischemic attack. There was a trend for treatment with a combination of aspirin and dipyridamole to reduce the risk of recurrent thrombotic events after adjusting for sex and ethnicity.