The prevalence of delirium in the Intensive Care Unit (ICU) is reported to vary from 20 to 80 %. Delirium in the ICU is not only a frightening experience for the patient and his or her family, it is also a challenge for the nurses and physicians taking care of the patient. Furthermore, it is also associated with worse outcome, prolonged hospitalisation, increased costs, long-term cognitive impairment and higher mortality rates. Thus, strategies to prevent ICU-delirium in addition to the early diagnosis and treatment of delirium are important. The pathophysiology of delirium is still incompletely understood, but numerous risk factors for the development of delirium have been identified in ICU-patients, among which are potentially modifiable factors such as metabolic disturbances, hypotension, anaemia, fever and infection. Key factors are the prevention and management of common risk factors, including avoiding overzealous sedation and analgesia and creating an environment that enhances reintegration. Once delirium is diagnosed, treatment consists of the use of typical and atypical antipsychotics. Haloperidol is still the drug of choice for the treatment of delirium and can be given intravenously in incremental doses of 1 to 2 to 5 (to 10) mg every 15 - 20 minutes.