Diffusion tensor imaging (DTI) is a valuable medical imaging technique for characterizing white matter (WM) in the brain. Numerous DTI studies have demonstrated reduced WM integrity in samples with autism spectrum disorder (ASD) diagnoses, as evidenced by lower fractional anisotropy (FA) values, especially in the corpus callosum (CC) (Hrdlicka, 2019), suggesting the potential of developing imaging biomarkers. This requires large sample sizes that can be achieved by aggregating data across multiple studies. This is hampered by variations in both equipment and scanner parameters, leading to confounding between site-specific effects and biological covariates. It is common to attempt to mitigate site effects by including a site term in analysis. Alternatively, data harmonization with ComBat (Fortin et al, 2018) obviates the need to control for site during analysis, allowing integration of patient data from different sources. The goal of this project is to demonstrate the importance of ComBat harmonization in mitigating non-biological site-specific sources of variation (equipment, scan parameters). Another goal was to determine if clinical group differences are enhanced after data harmonization.