Intensive care unit (ICU) delirium is widespread and occurs in 20% to 80% of patients. It can be assessed with ICU-validated scoring tools. The most commonly used tools include the Confusion Assessment Method for the ICU and the Intensive Care Delirium Screening Checklist. Since ICU delirium is associated with increased morbidity and mortality, it is imperative that risk factors are identified and prevented. Risk factors include predisposing factors such as history of alcohol abuse, dementia, or hypertension and precipitating factors such as immobilization, oversedation, higher severity of illness, and use of certain psychoactive medications such as benzodiazepines. Pharmacologic treatment with atypical antipsychotics may be used to reduce the duration of delirium if prevention is not successful. However, because of the adverse effects associated with these treatments, close monitoring for side effects is warranted.