Background Injuries in children occur most often in physical activity–related activities. A lot of these injuries result in direct and indirect costs. A detailed overview of the economic burden of those injuries in children is lacking.

Method A prospective study was conducted with 996 children in Dutch primary schools to describe the economic burden of injuries that occur during organised sports, leisure time and physical education (PE) class activities. Injuries were continuously monitored by PE teachers during the school year 2006–2007. An injury was recorded if it occurred during PE class, leisure time or organised sports activity and caused the child to at least stop the current activity. If an injury was recorded, parents received a cost diary to report the direct and indirect costs of the child's injury. Costs were collected from a societal perspective.

Results During one school year, a total of 119 injuries were reported by 104 children. The mean total costs as a result of an injury were €188±317. The mean direct costs as a result of an injury were much higher than the mean indirect costs (€131±213 and €57±159, respectively). The highest costs were found for upper extremity and leisure time injuries.

Conclusion Physical activity–related injuries are common in children and result in medical costs. Injuries that lead to the highest costs are those that occur during leisure time activities and upper extremity injuries. Intervention programmes for children to prevent upper extremity injuries and leisure time activity injuries may reduce direct (ie, healthcare) and indirect costs.

Trial registration: ISRCTN78846684