A considerable number of patients with psychiatric/ )`neurologic disorders are scheduled to receive operation and anesthesia. Antipsychotic drugs administered to schizophrenic patients should be continued before anesthesia for decreasing postoperative delirium. Schizophrenic patients are at 'risk for perioperative complications such as hypotension and lethal arrhyth- mia during anesthesia, postoperative ileus, and neuro- leptic malignant syndrome. Patients with depression may be predisposed to perioperative problems such as hypotension, serotonin syndrome and discontinuation syndrome. Antidepressants should be continued to avoid postoperative delirium. Anticonvulsants are diffi- cult to maintain their therapeutic and effective blood concentrations. It is important to continue anticonvul- sant therapy to avoid perioperative seizures except epilepsy surgery. Drug interactions of anticonvulsants are common especially with muscle relaxants. Discon- tinuation of anti-Parkinsonian drugs before surgery causes an exacerbation of Parkinsonism and sometimes Parkinsonism-hyperpyrexia syndrome. But, monoamine oxidase B (MAO-B) inhibitor should be discontinued at least two weeks before surgery because of severe drug interactions with pethidine. It remains unclear whether anesthesia and surgery are associated with a risk of Alzheimer's disease. During the perioperative period, cooperation among anesthesiologists, neurologists, psy- chiatrists, and surgeons is essential. It is important that medical experts share awareness about perioperative problems and their management in patients with psy- chiatric/neurologic disorder.