BACKGROUND: Prevention of injury among athletes is of paramount importance for sport events. The incidence of injury differs depending on many factors, such as level of competition, type of sport, and standard of surveillance systems. It is our purpose to provide a descriptive epidemiology of a national level competition multi-sports event. METHODS: During the 2008 Thailand National "Phitsanulok" Games, official medical teams of the various sports completed a report form after each match or competition. The demographic data, type of sport, details of injury or illness, diagnosis, and treatment were collected from the PLKGames 2008 program and analyzed by the Medical Surveillance Committee. RESULTS: There were 14,429 athletes and staff participating in the "Phitsanulok" games. A total of 496 injuries were reported during the competition, of which 300 male and 196 female athletes sustained injuries, resulting in an incidence rate of 4.1 injuries per 100 registered athletes. For all sports, 71, 50 and 38 injuries occurred during Rugby, Handball and Basketball, respectively, which accounted for 32% of all injuries. No injury was reported from many sports, such as table tennis, shooting, dancing, and golf The most common diagnoses were sprains and strains. About half of injuries were caused by contact with another athlete, followed by noncontact (28.6%) and limited-contact incidences (27.6%). According to the number of athletes, the risk of incurring an injury was highest in Pencak Silat, handball, basketball, and rugby football. About half of injuries affected lower extremities, while 135, 53, and 49 injuries involved upper extremity, head & neck, and axial body parts, respectively. The knee and ankle were the most common sites of injury. CONCLUSION: The data demonstrates a potential risk of injury occurring predominately in full-contact sports and limited-contact sports. The data is potentially useful in developing injury surveillance systems for future sporting events.