Quetiapine, an atypical antipsychotic, is widely used to treat delirium in intensive care units (ICUs). Studies demonstrate its efficacy and favorable safety profile. We report a case of an elderly patient who developed clinical and biochemical evidence of neuroleptic malignant syndrome (NMS) 5 days after quetiapine was commenced. Signs of NMS resolved after discontinuation of quetiapine and administration of dantrolene. Quetiapine-induced NMS has occurred with long-term use in the elderly in the outpatient setting. However, NMS has not previously been reported after treatment of ICU delirium. NMS is an important complication to consider before prescribing quetiapine in the ICU.