Objective. This study determines the injury rate (%) and the associated direct medical and indirect costs of sports injuries in Flanders. Setting. Epidemiological cohort designs and a human capital method were set up to measure respectively the medical direct and indirect cost of sports injuries. Participants. Seventy-two out of 82 Flemish sports federations participated. Intervention. Insurance statistics from 2003 were used to determine the overall rate of injury and injury localisations. Using these data, the medical direct cost and the impact sports injuries have on indirect costs are estimated. The indirect costs were determined by multiplying the days of absence from work with the daily cost resulting from a loss of production, being 200€. Main outcome. The total direct medical cost extrapolated for the Flemish sports participants was 15,027,423 €, which amounted to 0.07% to 0.08% of the total budget spent on health care. The indirect cost extrapolated for the Flemish sports participants was 111,420,813 €, which is about 3.4% of the costs arising from absenteeism from work. Results. Of the 14 in-depth analysed sports, the rate of injury was highest in European team handball (8.96% [95% CI: 8.95-8.96]) and lowest in swimming (0.62% [95% CI: 0.62-0.62]). The highest direct medical cost was found for ACL-injuries (1,358€ per injury) and the lowest for foot injuries (52€ per injury). Conclusion. The costs calculated here can become critical statistics in medical care debates. Data obtained here will enable us to make a cost-benefit analysis of the impact of preventive measures.