In summary, their are a great many causes of mental retardation, each of which must be investigated carefully prior to induction of anesthesia. There are a few basic points to be remembered, no matter what the disease: (1) establish how much the patient understands and whether or not the patient can communicate, (2) establish whatever rapport is possible and use that both preoperatively and postoperatively in place of medication if possible, (3) avoid early extubation, and (4) be prepared for fairly long-term ventilation if the child cannot cooperate. The choice of anesthetic agents and preoperative and postoperative medications, their route of administration, and amount will be dictated by the disease entity, its severity, and the scope of the contemplated surgery.