Fetal alcohol spectrum disorder (FASD) is the umbrella term used to describe the various developmental disorders associated with prenatal alcohol exposure. Individuals with FASD often have a variety of cognitive, behavioral, and neurological deficits stemming from structural brain damage. One critical aspect is the white matter forming the brain connections for efficient communication between brain regions. Diffusion tensor imaging (DTI), an advanced magnetic resonance imaging technique that measures the degree and directionality of water diffusion, can identify specific white matter tracts noninvasively and provide quantitative parameters that are more sensitive to underlying microstructural tissue changes than conventional imaging. This chapter provides a brief overview of DTI and outlines the seven previous studies that have used DTI to examine brain abnormalities in children, adolescents and young adults prenatally exposed to alcohol. Although the studies used subjects with different diagnoses and ages, there are several consistent findings. The corpus callosum, particularly the posterior section, and the white matter of the temporal lobe have repeatedly emerged as abnormal. The right hemisphere is more consistently implicated than the left, suggesting interesting asymmetries in the FASD population. Several studies have linked cognitive (dis)ability, including working memory and visuomotor integration, to diffusion parameters reflecting the underlying brain structure. Noninvasive imaging, such as DTI of the white matter, can document and help to further understand the effects of prenatal alcohol exposure on the brain and the consequences for cognition and behavior.