Ice hockey is the second most popular sport in Czechoslovakia. The membership of all registered players in a national organization together with their collective injury insurance enabled us to make an analysis of the various factors contributing to ice hockey injuries in this country. In 1967 and 1968, 3,895 injuries were registered among 65,881 players. The authors consider the knowledge of the causes and mechanisms of injuries as one of the most important conditions for initiating effective prevention of injuries. It was found that in ice hockey the most frequent cause of injury is the factor of personal physical contact with other players (82.1%), while the most frequent injury mechanism is a blow or hit by an object (53.9%). Further, the reported injuries have been evaluated with respect to the stricken parts of the body. Most injuries were located on the head (36.7%). Differentiating the injuries with respect to organs and tissues affected, we found that the majority of injuries involved the skin (37%). Analysis of the collected injury records suggested the following guidelines for prevention: greater care ought to be devoted to the sportsmanship education of the players, and to a systematic improvement of appropriate protective equipments, especially safeguarding against hits by the puck and blows with the hockey stick.