Diffusion tensor imaging is a non-invasive magnetic resonance imaging technique that describe the orientation and location of white matter tracts in vivo, it guides the surgeon regarding the relationship of the intra-axial tumor to adjacent white matter tracts in different planes. Routine pre-surgical FMRI allows for assessment of the relationship between brain tumor and motor cortex to facilitate function-preserving surgery and reduce postoperative morbidity. The purpose of this study is to evaluate role of diffusion tensor magnetic resonance imaging, fiber tractography and motor functional MRI in assessment of white matter tracts affected by the tumor, and to utilize this information in guiding surgeons. Fifty patients with different types of brain tumors were enrolled in this study. Fiber tracts involvement were classified into four categories (edema, displacement, infiltration and disruption), comparison between benign and malignant tumors groups as regards to the patterns of fiber tracts involvement were done. The prevalence of edema and displacement was higher among the benign group while prevalence of infiltration and disruption was higher among the malignant group. Localization of the primary motor hand area with functional MRI was done, The relation of it to the tumor was measured. Treatment plans before and after DTI & functional MR imaging differed in 35 patients as regard to surgical approach and in 17 patients as regard to modification of extent of resection with significant relation. Diffusion tensor imaging DTI represents recent important progress in the field of diagnostic imaging. It is the only technique that is able to visualize in vivo white-matter tracts so that it is of great help in preoperative neurosurgical planning.