We report an unusual case of thrombocytopenia associated with neuroleptic malignant syndrome (NMS). A 31-year-old Black male with a history of hypertension, partial seizures, and schizophrenia developed acute rigidity closely followed by severe hyperpyrexia (temperature 102 degree F), tachypnea, and tachycardia. His home medications at the time of presentation included propanolol 10 mg tid, haloperidol 10 mg bid, sodium valproate 500 mg bid, benztropine 1 mg bid, and haloperidol decanoate 100 mg i.m. every 3 weeks, from another psychiatric facility. Despite vigorous therapy for the hyperthermia, he rapidly developed significant hypoxia requiring mechanical ventilation. A diagnosis of neuroleptic malignant syndrome was made and the patient continued to receive aggressive supportive care. On hospital day 2 his platelet count dropped to 47,000/microl and bottomed out at 36,000/microl by day 3 with other blood cell counts remaining within normal limits. Over the next few days he showed rapid clinical improvement with normalization of his blood chemistries and he was discharged home after 5 days of hospitalization in good condition.