Major advances in surgical and cardiopulmonary bypass technology have occurred in the past 30 years. Total correction of previously inoperable congenital cardiac defects is being performed with increasing frequency and in children at progressively younger ages. While the majority of children undergoing cardiac surgery survive without incident, increasing concern is being raised about neurologic sequelae seen in some survivors. Complications such as embolization, hypoxia, inadequate cerebral perfusion, and biochemical disturbances may all lead to brain damage following cardiac surgery. Acute postoperative neurologic problems include seizures, impaired levels of consciousness, focal motor deficits, and movement disorders. Long-term sequelae include language and learning disorders, mental retardation, seizures, and cerebral palsy. Intraoperative cerebral monitoring techniques are as yet imperfect, but their use in combination with meticulous intraoperative and postoperative care currently provides the best means of reducing neurologic morbidity. Future studies should explore other methods of preserving neurologic integrity in children undergoing open heart surgery.