Neuroleptic malignant syndrome (NMS) is an uncommon but potentially fatal idiosyncratic reaction characterized by the development of altered consciousness, hyperthermia, autonomic dysfunction, and muscular rigidity on exposure to neuroleptic medications. NMS commonly develops during the initial phases of treatment, when the drug dose is being stepped up, or when a second drug is introduced. Although various risk factors have been proposed, the exact etiology is unknown. The mortality and morbidity associated with NMS can be decreased with early recognition, early discontinuation of the neuroleptics and aggressive treatment. In this case report, a schizophrenia patient who developed NMS without hyperthermia and obvious autonomic dysfunction after single use of olanzapine will be discussed. His symptoms of loss of consciousness, dystonia and urinary and fecal incontinence continued and 6 months later, he died due to cardiopulmonary arrest.