We investigated the relationship between the severity of ski injuries (n = 895) classified according to the abbreviated injury score (AIS
based on objective criteria for judging the severity of injuries) and the following factors: sex, site and mode of injury, skill level, speed at the time of injury, binding release, gradient, type of snow, surface conditions, weather, visibility, and the month and day of the week on which the injury was sustained. Age, sex, mode and site of injury, speed at the time of injury, binding release, visibility, and the month and day of the week on which the injury was sustained were associated with the severity of injuries, but the skill level, gradient, type of snow, surface conditions, and weather were not. Injuries with an AIS of 4 or higher accounted for only 4.6% of injuries (AIS scores range from 1: e.g., mild sprains, to a maximum of 6: injuries with scores of 4 and above are regarded as life-threatening). Given that patients with very severe injuries tend to be taken to our facility, the actual incidence of severe ski injuries may be even lower. However, measures to protect against severe injuries are needed to ensure greater safety for skiers.