SummaryBassetti CL. Differential diagnosis and management of non-psychiatric acute confusional states. Schweiz Arch Neurol Psychiatr. 2007;158:368-78. Acute confusional states (ACS, syn. delirium) represent a medical emergency with significant morbidity, mortality and socio-economic consequences. This paper offers an overview on nonpsychiatric causes of acute confusional states and their management. Identification of risk and precipitating factors for acute confusional states, neurological (stroke, traumatic brain injury, encephalitis, non-convulsive status epilepticus, etc.) and non-neurological causes (metabolic-septic encephalopathies, intoxications/poisonings, etc.) of acute confusional states and occurrence of acute confusional states in special settings (intensive care unit, postoperative situation, advanced cancer) are discussed first. Differential diagnosis, diagnostic work-up and treatment strategies of non-psychiatric acute confusional states are then presented. The review is completed with six clinical vignettes.