Exposure to repeated high-velocity impacts may contribute to increased risk of cognitive impairment. However, there has been limited long-term longitudinal investigations into brain tissue change in high-impact sports. In this large 4-year longitudinal DTI study, high (football) and low-contact (volleyball) athletes show a temporal double dissociation in cortical microstructure: in both the frontal and temporal lobes, cortical FA increases over time in volleyball compared to football. While an increase in ICVF underlies this FA increase in frontal cortex, a decrease in ODI underlies this FA increase in temporal cortex. Exposure to high-impact sports may alter cortical microstructural development.