Delirium is a neuropsychiatric syndrome characterized by impairment of consciousness, changes in cognition, or perceptual disturbances. In addition, delirium is often accompanied by delusions, hallucinations, and agitation. In this study, 12 older patients with delirium were treated for neuropsychiatric symptoms with quetiapine. The mean duration for stabilization was 5.91 +/- 2.22 days, and the mean dose was 93.75 +/- 23.31 mg/day. None of the 12 patients developed extrapyramidal symptoms. There were significant improvements on all measures used in this study. Interestingly, the Delirium Rating Scale scores along with scores of the Mini-Mental State Examination and Clock Drawing Test continued to improve throughout the 3-month study period. In our study, we found that quetiapine was a safe and effective treatment in hospitalized older patients with delirium.