Physical activity accounts for up to 17% of the variance in bone mineral density (BMD). Specifically, weight bearing exercises are of critical importance in increasing BMD. The aim of the present study was to evaluate the influence of three different sports with different mechanical loading properties on BMD of young athletes. This was an observational retrospective cohort study. All available medical records of adolescent athletes who have been followed at the Division of Adolescent Medicine at Hacettepe University were reviewed. Bone mineral content (BMC) and BMD of lumbar spine (L1-L4) and left femoral region were compared between young athletes participating in swimming (n=50), pentathlon (n=18), and figure skating (n=7). Femur total and lumbar spine (L1-L4) BMC values of figure skaters (29.1 +/- 8.1 g and 51.5 +/- 19.0 g, respectively) were found to be higher than swimmers (21.5 +/- 6.6 g and 36.1 +/- 11.7 g, respectively) and pentathletes (21.6 +/- 6.2 g and 41.7 +/- 19.4 g, respectively). However, there were no significant differences between any of the groups in lumbar spine and left proximal femur measurements. Regarding BMD, figure skaters (1.1 +/- 0.2 g/cm(2)) had significantly higher femur total BMD values than pentathletes (0.9 +/- 0.1 g/cm(2)) and swimmers (0.9 +/- 0.1 g/cm(2), p <0.05). The type of sport has an impact on BMD. Weight bearing and high impact loading activities seem to be associated with a better bone density in a region specific manner. Recommendation of high impact loading exercises may be considered to improve bone health in young athletes especially participating in low impact and non-weight bearing sports.