White matter in the brain is comprised of densely packed, mostly myelinated axons that interconnect gray matter regions, forming functional circuits, or networks. Its integrity is thus important in providing uninterrupted communication between axonal bodies throughout the brain, and proper function of aforementioned networks. Diffusion tensor imaging (DTI) has become one of the major tools in clinical and experimental neuroscience, and the most important imaging technique to investigate brain white matter in vivo. Schizophrenia, a widely studied but still poorly understood neuropsychiatric disorder, has been characterized as multifocal brain disease, involving abnormal brain connectivity. The idea of quantifying abnormalities within white matter fiber tracts, which subserve anatomical connections between distant as well as proximal brain regions, has thus fueled an interest in DTI studies in schizophrenia, resulting, to date, in more than 70 original peer-reviewed publications. A deeper understanding of white matter anatomy is, nonetheless, essential for understanding further the relationship between the anatomy and function of distributed neuronal systems. Such knowledge is also extremely important for clinical purposes. DTI is based on probing the movement of water molecules within the tissue environment. In brain tissues, the presence of different tissue components restricts Brownian motion. In gray matter, and in some peripheral white matter regions, when averaged over the macroscopic scale of image voxels, the degree of the restriction of water diffusion is similar in every direction, and diffusion is said to be isotropic. Two of the biggest problems in interpreting DTI findings are the lack consistency across studies and the lack of microstructural specificity for the diffusion measures that are employed.