An air ambulance is an aircraft used for emergency medical assistance in situations where either a traditional ambulance cannot reach the scene easily or quickly enough, or the patient needs to be transported over a distance or terrain that makes air transportation the most practical transport. They can also aid in the search for missing or wanted people. These and related operations are referred to as Aeromedical. Air ambulance crews are supplied with equipment that enables them to provide medical treatment to a critically injured or ill patient. Common equipment for air ambulances includes ventilators, medication, an ECG and monitoring unit, CPR equipment, and stretchers. An important distinction should be made between a medically staffed and equipped air ambulance which can provide medical care in flight, and the use of a non-medicalized aircraft simply for patient transportation, without care in flight. The military and NATO refer to the former as "Medical Evacuation (MEDEVAC)" and to the latter as "Casualty Evacuation (CASEVAC)" respectively.

Die Luftrettung ist der Einsatz von Rettungsmitteln über den Luftweg in der Notfallmedizin. Die Luftrettung kommt dann zum Einsatz wenn aufgrund der Lage ein schnelleres Eingreifen als durch bodengebundene Rettungsdienste möglich ist. Das kommt meist in ländlichen Gebieten vor, wo dann meist ein Rettungshubschrauber verwendet wird; es fliegt aber z. B. in Australien im Outback der Flying Doctor Service Notfall- und auch reguläre ärztliche Einsätze mit Flugzeugen.