Macroscopic and microscopic emboli of gas, biologic aggregates, and inorganic debris can occur during cardiac operations with cardiopulmonary bypass and may result in end-organ ischemia. In the current era pump-generated embolism is a diminishing cause of perioperative neurologic injury, which now appears to be related mostly to atheroembolism from manipulation of the atherosclerotic ascending aorta, and presents a continuing technical challenge to the surgeon.