Patients with symptomatic intracranial atherosclerotic stenosis >70% have a 1-year stroke recurrence rate of up to 23% in the area supplied by the diseased artery, whereas patients with stenosis <70% have a significantly lower rate of ipsilateral stroke (<10%). There is currently no data to support intervention in patients with asymptomatic intracranial stenosis, so patients with symptomatic intracranial stenosis ≥70% stenosis are most likely to benefit from intervention. When is intervention best? Similar to patients with symptomatic carotid stenosis, current data show that the risk of recurrent ischemic vascular events in the short term is highest in the group of patients who meet the criteria for intervention and who are also responsible for the current responsible clinical event. Therefore, intervention should be considered at the appropriate time in cases that continue to have episodes despite medical therapy or have poorly compensated collateral circulation.