Delirium is a common, disruptive, costly, and at times lethal condition found among patients in the acute care setting. Nurses can be the first to discover its presence and thereby reduce the time to treatment. Identifying delirium requires a knowledge of its clinical features, a mastery of the bedside cognitive mental status examination, critical judgment in distinguishing delirium from other psychiatric disorders, and appropriate nursing interventions based on ongoing assessment. In this article we review elements of such an approach and illustrate common clinical challenges for nurses with case examples.