Modern US Army rotary wing aeromedical evacuation operations and doctrinal concepts can be traced back to the Korean and Vietnam Wars. These early concepts have formed the foundation for the current doctrine, structure, and employment of aeromedical evacuation assets on the battlefields of today. Aeromedical evacuation operations performed during the Korean and Vietnam Wars were executed in an exceptional manner. The medical personnel, hospital system, medical evacuation, and many other medical functions all contributed to the overall success of medical operations. The overall purpose of this research is to identify and describe the major historical operational factors of US Army rotary wing aeromedical evacuation system in the Korean and Vietnam Wars. The successful operations of US Army rotary wing aeromedical evacuation system in each of these wars permit a historical comparison between them.