Delirium is a complex neuropsychiatric syndrome with an acute onset and fluctuating course; it is common in all medical settings. Delirium occurs in about 15-20% of all general admissions to hospital1; it occurs with higher frequency in elderly people and in those with pre-existing cognitive impairment.2 Delirium has many synonyms, reflecting its ubiquitous nature rather than distinct conditions. These synonyms include acute brain failure, acute confusional state, and post-operative psychosis. Delirium has not been well studied owing to methodological difficulties and a lack of consensus about its definition. Thus, delirium has been underappreciated as an independent entity that requires therapeutic intervention beyond identification of the syndrome and amelioration of the underlying cause. The development of a clearer definition, improved detection and assessment tools, and recognition of the significant independent morbidity associated with delirium have substantially changed this situation. These developments coupled with a greater awareness of the needs of an increasingly large population of elderly people3 make a review of the day to day management of patients with delirium timely.