While rates of regular physical activity are increasing among Australians, there is potential for an increase in the number of injuries. It is important therefore to consider the benefits attributed to participation in sport and recreational pursuits in the light of the increased physical risks. 1Until now, there has been a lack of valid, reliable, and recent data on the incidence and up to date costs of sports injuries in Australia. Furthermore, much of the research has focused on elite participants, 2 with a paucity of research among non-elite sports participants, despite the fact that most sports participants play at a non-elite level. 3 As the risk of injury and the concomitant rate of injury are likely to be different in elite and non-elite sports participants, there was a need for research that could be translated into injury prevention policy and practice for non-elite sports participants.A proposal to establish the first Australian longitudinal population based study of sports injuries—the Western Australian sports injury study—was developed in collaboration with the peak non-government organisation for sports medicine in Australia—Sports Medicine Australia—and the authors. The broad aims of the study were to:determine the magnitude of the sports injury problem at the non-elite level of participation in Western Australia;determine the cost of sports injuries to the Western Australian community;provide an evidence base for the enhancement and upgrading of existing sports injury prevention and education programmes.