Delirium, or acute confusional disorder, is a frequent occurrence in older people admitted for an acute pathological condition and it complicates hospitalization, worsening the prognosis. The clinical picture of delirium is characterized by an acute onset and a fluctuating course, inattention, disorganized thinking, altered level of consciousness (see CAM: Confusion Assessment Method for the diagnosis of delirium) and the presentation can take two main forms, either hyperactive or hypoactive, which sometimes coexist. The onset of an acute confusional state, especially in patients with a previous normal cognitive status, represents a condition that raises a lot of distress for their families or caregivers. In order to properly face delirium it is essential first to recognize it as a disease, but this behavior does not always occur in our wards.