The Intensivist is a physician who specialises in the resuscitation, stabilisation and treatment of patients who have suffered severe and lifethreatening illnesses or injuries and acute organ failure. The practice of Intensive care (critical care) medicine includes the provision of organ system support, the investigation, diagnosis, and treatment of acute illness, systems management and patient safety, ethics, end-of-life care, and the support of families.

The intensivist is a multidisciplinary role and the physician may come from a background in internal medicine, anaesthesia, emergency medicine, general surgery or paediatrics and will have completed additional training in intensive care medicine. The intensivist may work in a general intensive care unit or specialised intensive care unit such as surgical intensive care, trauma  intensive care, neurological  intensive care, cardiac intensive care or mobile  intensive care.

Intensivist roles are hospital based and usually in the larger secondary and tertiary care hospitals. Working patterns vary according to the institution and can be a standard working week with on call duties or a shift system.  Intensivist shortages are common in most countries and there are usually many roles available worldwide.