Delirium is a classic geriatric syndrome that occurs commonly among the frail elders who make up many of the residents in postacute and long-term care facilities. The prevalence of the disorder in these settings may be increasing as a result of the pressure to reduce hospital length of stay. Clinicians often do not recognize when patients in their care are delirious, but simple and practical means exist to allow its diagnosis. Those who practice in long-term care must be knowledgeable about the risk factors for the disorder, as well as how to recognize, diagnose, prevent, and treat it.