A review of hemorrhagic transformation after brain ischemia is presented. The pathological, clinical and radiological aspects are discussed with respect to recent studies. The different pathophysiological mechanisms (reperfusion, vascular rupture, size of infarction, timing of constitution) are reviewed. The role of the utilization of antithrombotic (anticoagulant and thrombolytic) agents in the production of hemorrhagic infarct is presented, and we propose a new classification of hemorrhagic infarct, based on the CT scan patterns.