Herein we report the case of a patient with antiphospholipid Syndrome (APS) and an ischemic stroke suffered while he was anticoagulated, and we discuss the usefulness of magnetic resonance angiography in the early diagnosis of such a complication. We also attempt to emphasize the great value of an individual risk evaluation when warfarin therapy is introduced. In fact, our case supports the importance of high-intensity anticoagulation in patients with multiple thrombotic recurrences, and the exceptional value that strict anticoagulation control has in this kind of patients.