Delirium is a syndrome characterised by a disturbance of consciousness (often fluctuating), cognition and perception. In terminally ill patients it is one of the most common causes of admission to clinical care. Delirium may arise from any number of causes and treatment should be directed at addressing these causes rather than the symptom cluster. In cases where this is not possible, or treatment does not prove successful, the use of drug therapy to manage the symptoms may become necessary. This is an update of the review published on 'Drug therapy for delirium in terminally ill adult patients' in The Cochrane Library 2004, Issue 2 ( Jackson 2004).