BACKGROUND AND OBJECTIVE: To update the ad hoc Committee of the Cerebrovascular Diseases Study Group of The Spanish Neurological Society guidelines on prevention of ischemic stroke (IS) and Transient Ischaemic Attack (TIA). METHODS: We reviewed the available evidence on ischaemic stroke and TIA prevention according to aetiological subtype. Levels of evidence and recommendation levels are based on the classification of the Centre for Evidence-Based Medicine. RESULTS: In atherothrombotic IS, antiplatelet therapy and revascularization procedures in selected cases of ipsilateral carotid stenosis (70-99%) reduce the risk of recurrences. In cardioembolic IS (atrial fibrillation, valvular diseases, prosthetic valves and myocardial infarction with mural thrombus) prevention is based on the use of oral anticoagulants. Preventive therapies for uncommon causes of IS will depend on the aetiology. In the case of cerebral venous thrombosis oral anticoagulation is effective. CONCLUSIONS: We conclude with recommendations for clinical practice in prevention of IS according to the aetiological subtype presented by the patient.