Neuroleptic malignant syndrome (NMS) is a rare and life-threatening complication of antipsychotic treatment. It is considered to occur due to dopaminergic blockage in central nervous system. Clinical picture of NMS consists of muscle rigidity, hyperthermia, autonomic dysfunction and clouding of consciousness. In this paper, 35 year-old female patient with bipolar mood disorder, while maintaining in lithium treatment for five years, after the addition of haloperidol, occurring NMS is presented. A 35-year-old female patient was admitted to emergency service with the complaints of high fever, sweating, clouding of consciousness and speech disturbance. She was on lithium therapy with a diagnosis of bipolar mood disorder for the last five years. 2 months ago, due to the complaints of loss of appetite, insomnia, irritability, increase in self-care and amount of speech, psychiatric medication was arranged as lithium 600 mg/day and haloperidol 30 mg/day (i.m) and biperidene 10 mg/day (i.m) by her psychiatrist. On the sixth day of the patient’s treatment, she was admitted to the hospital because of the development of NMS. After administration of antipsychotic drugs, particularly hyperthermia, rigidity, altered consciousness when deemed, leukocyte count, CPK levels and blood pressure should be monitored closely. In patients suspected of NMS, which can be fatal in terms of results, as well as supportive therapy, rapid initiation of bromocriptine and/or dantrolene could be a life-saving approach. Including particularly parenteral, multiple, high doses and in particular the use of high-potency antipsychotics may increase the risk of NMS should be considered. Although antipsychotic drugs are being highlighted for the risk of NMS, importance of the lithium use in terms of the risk of NMS and an increase in this risk with lithium used in conjunction with antipsychotic treatment should be considered. In our case, responding well to treatment and in recovery without squeal; the early diagnosis and antipsychotic drugs be discontinued immediately and it is important to begin bromocriptine treatment in addition to supportive therapy.