The aim of this study was to characterize acute, subacute and chronic changes in the brain following sport-related concussion in a group of young athletes. Diffusion kurtosis tensor parameters were compared between concussed athletes and controls. The concussed group demonstrated widespread increase in axial kurtosis compared to the controls at the acute time point, which gradually diminished over the course of 14 days. Conversely, alterations in radial kurtosis were mostly in the frontal white and gray matter and occipital gray matter regions. These findings may have important implications for the clinical management of sport-related concussions.