Delirium is common, morbid and costly, especially among hospitalised elderly patients. Nonetheless, it remains under-recognised and often poorly managed. This article summarises the 5 key steps in the optimal management of delirium. The first step is to precisely define the syndrome of delirium, using key features described in the Diagnostic and Statistical Manual of Mental Disorders (fourth edition) [DSM-IV] or the Confusion Assessment Method. Key features include an acute onset of mental status change, fluctuating course, the presence of inattention, and either disorganised thinking or an altered level of consciousness. The second step involves the identification of patients at high risk of delirium before it develops, so that preventive measures can be implemented. Risk factors for delirium include advanced age, dementia, impaired functional status, chronic comorbidities and medications, and the severity of the acute illness or surgery. The third step is improved recognition of delirium. Very often, the presence of delirium is neither diagnosed nor properly documented in the medical record. The fourth step is to appropriately evaluate the delirious patient to assess all important contributors to the syndrome. This evaluation will usually involve a careful history, medication review, physical examination and selected laboratory testing. The fifth, and most important, step is the management of the delirious patient. The key elements of management are treating the primary condition(s) leading to delirium, removing all treatable contributing factors, maintaining behavioural control, and supporting the patient and their family.