An increasing participation in ultra-endurance foot races is cause for greater need to ensure the presence of appropriate medical care at these events. Unique medical challenges result from the extreme physical demands these events place on participants, the often remote settings spanning broad geographical areas, and the potential for extremes in weather conditions and various environmental hazards. Medical issues in these events can adversely affect race performance, and there is the potential for the presentation of life-threatening issues such as exercise-associated hyponatremia, severe altitude illnesses, and major trauma from falls or animal attacks. Organization of a medical support system for ultra-endurance foot races starts with a determination of the level of medical support that is appropriate and feasible for the event. Once that is defined, various legal considerations and organizational issues must be addressed, and medical guidelines and protocols should be developed. While there is no specific or universal standard of medical care for ultra-endurance foot races since a variety of factors determine the level and type of medical services that are appropriate and feasible, the minimum level of services that each event should have in place is a plan for emergency transport of injured or ill participants, pacers, spectators and event personnel to local medical facilities.