Recent studies have demonstrated diffusion tensor imaging tractography of cranial nerves (CNs). Spatial and angular resolution, however, is limited with this imaging technique. In this study, we reported our experience in CNs tractography detailing the influence of ROI design. We demonstrated that understanding in detail the key role of ROI design and its influence helps to provide coherent tracts. We expect this work to enable a more reliable CNs tractography and made it a useful tool for surgical planning of complex skull base tumors.