Patients with dementia with Lewy bodies (DLB) are particularly vulnerable to adverse effects of neuroleptics; this sensitivity is included among the clinical diagnostic criteria for DLB. Recently atypical neuroleptics, which carry less risk of extrapyramidal side effects than typical agents, have come into increasing use in treating psychotic symptoms and behavioral disturbances related to DLB. The present report is the first to describe a DLB patient who developed neuroleptic malignant syndrome (NMS) induced by quetiapine, an atypical neuroleptic known to have relatively infrequent extrapyramidal side effects in DLB patients. Physicians should be aware of the possibility of the occurrence of NMS in DLB even when atypical neuroleptics are administered.