Sport is well known as a common cause of dental and oral injuries. Sports-related injuries account for 13% to 39% of all trauma cases in this area. The knowledge about prevention of dental and oral injuries among hobby and professional athletes can be regarded as not satisfactory yet. Mouth guards are considered as one of the most effective means for injury prevention. However, no statements or recommendations regarding use of mouth guards in sports have been published in German language literature yet. The following review article describes several types of available mouth guards and discuss their advantages and disadvantages. Guidelines concerning indications and use of mouth guards are presented.