Delirium is a common, serious problem for hospitalized older patients. Recognition of delirium poses challenges requiring cognitive assessment and knowledge of the clinical course. Delirium often is of multiple causes and is associated with a poor long-term prognosis. Nonpharmacologic approaches for delirium management are recommended; pharmacologic management should be reserved for patients who pose a danger to themselves or others. Importantly, delirium and its complications may be preventable through a targeted risk factor approach.