Thrombolytic therapy is the only treatment for acute ischemic stroke proven to improve clinical outcome. Identifying patients at higher risk for hemorrhagic transformation following thrombolysis is an important goal, and this information could increase the overall safety profile of thrombolytic therapy. The most comprehensive and informative data on the risk of thrombolysis-induced hemorrhage in the setting of cerebral microbleeds (CMBs) and acute stroke comes from the Bleeding Risk Analysis in Stroke Imaging before thrombolysis (BRASIL) study. In cerebral amyloid angiopathy (CAA), CMBs are located predominantly in lobar regions and the total number of lesions is often significant (10-75 or more). A lobar location is also a more common site for thrombolysis-related hemorrhages. In contrast, CMBs linked to hypertensive small vessel disease are typically located in predominantly deep regions and may be far fewer in number.