This study investigated the incidence of injury in German Bundesliga football based on the evaluation of two American football teams before and during the season 1995. Certified team physicians and team physiotherapists were the initial medical professionals providing on-site diagnosis, injury documentation and first aid for all injuries. An injury was defined as minor (group I) causing the player to miss practice or game sessions up to 1 week without requiring surgery; as severe (group II) causing the player to miss practice or game sessions for more than 1 week up to 3 months or requiring surgery; and as catastrophic (group III) if the incident led to treatment for more than 3 months, treatment in an intensive care unit or persistent neurological or orthopaedic disability or death. From the data collected it was possible to calculate the risk of injury per time of exposure per athlete. The athlete's function, influence of the weather and mechanisms of the injuries were registered. In total, 242 injuries were documented. The rate of injury was calculated as 16 per 1000 hours of practice and game per athlete. Severe injuries (group II) were found in 94 cases. Catastrophic injuries were not seen during the study. The knee was found to be the most common site of injury, while the ankle ranked second. Our study showed that the risk of injury in American football in German Bundesliga is comparable with soccer or handball.