A selective subtotal cerebellar neuronal degeneration was found in a patient who died 4 1/2 months after suffering neuroleptic malignant syndrome (NMS), a rare, potentially fatal disorder associated with neuroleptic medications. It is suggested that the cerebellar neuronal degeneration in this case was due to hyperpyrexia, a cardinal clinical feature of NMS. Similar pathologic findings appear not to have been previously reported in NMS but have been described in heat-induced central nervous system (CNS) injury. The findings imply that a cerebellar syndrome might be encountered in patients who survive NMS complicated by a particularly high febrile course.