A survey was performed of 961 Australian rules footballers of varying age and football ability in order to determine the prevalence of mouthguard use during training and match play. Emergency dental injury data was obtained to compare the frequency and timing of dental injury in a non-sporting community population. The prevalence of mouthguard use during match play varied between 60% for juniors and 90% for elite footballers whereas the mouthguard use during training ranged between 2% for junior and 40% for elite players. One third of players used over the counter 'boil & bite' mouthguards, generally considered unsatisfactory for dental protection. Of the players who did not currently use mouthguards, most had tried them previously but found them uncomfortable to wear. The community dental injury data showed that the majority of emergency dental injuries were due to sport and followed the temporal pattern of sports participation on week days and weekends. The prevalence of mouthguard use in this population was not known. This study has implications for the provision of emergency dental treatment for sport participants and for improved dental injury prevention measures to avoid expensive and potentially disfiguring dental injuries in young athletes.