A number of studies have examined the risk factors for Osgood-Schlatter disease (OSD). Studies on risk factors have not necessarily accurately demonstrated the risk factors of this disease because they were not prospective cohort studies or the populations in the studies were not categorized by the skeletal maturation of the tibial tuberosity. We can identify the precise risk factors for OSD by performing a prospective cohort study of a group of asymptomatic patients in particular times of adolescent using ultrasonography. In the present study, we aimed to investigate the precise risk factors for OSD.