Alcohol abuse and dependence disorders are common in the 10% of hospitalised patients who need admission to the intensive care unit (ICU), but these disorders are often undiagnosed. The systemic effects from the excessive use of alcohol increase susceptibility to, or directly cause various important disorders in the critically ill. Early recognition of alcohol abuse and dependence is necessary and should prompt consideration of several alcohol-specific diagnoses that have important prognostic and therapeutic implications for these patients. We discuss the use of screening tests to improve the identification of alcohol abuse and dependence disorders, the epidemiology and pathogenesis of important alcohol-related disorders, differences in the presentation of several common alcohol-related diagnoses in the ICU, and important alcohol-specific therapies.