Delirium, a serious and common manifestation of brain dysfunction in critically ill patients gained great attention over the last decade. Important risk factors such as use of benzodiazepines, coma, preexisting cognitive impairment, alcoholism and high severity of illness at ICU admission were i-dentified. Screening tools like the CAM-ICU and the ICDSC were extensively validated in many different ICU patient populations and are recommended for routine monitoring in everyday practice. Sedation with novel sedatives such as dexmedetomidine, implementation of non pharma-ceutical, preventive interventions and early mobilization of patients may reduce the incidence of this syndrome. The role of haloperidol and atypical antipsychotics in the prevention and treatment of ICU delirium is still under investigation.