Introduction: Neuroleptic malignant syndrome (NMS) is a rare but potentially life-threatening idiosyncratic reaction during the use of antipsychotic drugs, usually beginning in the first 2 weeks of the treatment. NMS is generally manifested by muscle rigidity, hyperthermia, autonomic instability, altered mental status, tremors, elevated serum creatinine phosphokinase, and leukocytosis.Case Report: A 26-year-old male patient who had a ventriculoperitoneal (V-P) shunt was admitted to the emergency department with complaints of loss of consciousness, fever, respiratory distress, and palpitations. In his history, we learned that treatment of quetiapine 25 mg/day was initiated 6 months ago. After physical examination and laboratory results, the patient, who had a V-P shunt, was primarily considered shunt dysfunction or infection. But, with laboratory parameters and radiographic examinations, we moved away from this diagnosis. He was evaluated as NMS due to the history of antipsychotic drug using, fever, rigidity, tachycardia, tachypnea, confusion, and increase of creatine phosphokinase for the preliminary diagnosis. Since there was no any etiological factor that could explain the clinical process, he was admitted to the medical intensive care with a diagnosis of NMS.Conclusion: NMS is a disorder that can be life-threatening and must be recognized by clinicians.