In last few years a unique clinical phenomenon of “ICU psychosis” or “Sun downing” in Intensive Care Unit (ICU) has been discussed. More recently, Eisendrath defined "ICU Syndrome" as an acute organic brain syndrome involving impaired intellectual functioning and occurring in patients treated within a critical care unit. "ICU psychosis" was present when the impairment prevented the patient from accurately judging reality.5 The aims of study understand about meaning of ICU psychosis, causes, signs and symptoms and management. ICU psychosis is dangerous because it impedes the delirium if not treated on time. So it is very necessary to understand about the topic and must be involved all medical and nursing professional in care to prevent it. This study will help to prevention and management of ICU psychosis.

Keywords: Intensive care unit: Psychosis; Sun downing.