Determining the cause of death when a restrained person suddenly dies is a problem for death investigators. Twenty-one cases of death during prone restraint are reported as examples of the common elements and range of variation in these apparently asphyxial events. A reasonable diagnosis of restraint asphyxia can usually be made after ruling out other causes and collecting supportive participant and witness statements in a timely fashion. Common elements in this syndrome include prone restraint with pressure on the upper torso; handcuffing, leg restraint, or hogtying; acute psychosis and agitation, often stimulant drug induced; physical exertion and struggle; and obesity. Establishing a temporal association between the restraint and the sudden loss of consciousness/death is critical to making a correct determination of cause of death.