AIM OF THE STUDY: To present differences in frontal aslant tract (FAT) tractography among patients diagnosed with primary brain tumours and metastatic brain tumours. MATERIAL AND METHODS: The analysis included 38 patients diagnosed with a frontal brain tumour. A control group of 30 healthy patients was also considered. The FAT was delineated, taking into account ROI 1 - the superior frontal gyrus, and ROI 2 - SMA. Endpoints were determined on the pars opercularis and pars triangularis of the inferior frontal gyrus. FAT was delineated in four different ways for each patient. RESULTS: In the group of patients with a brain tumour, a lower volume of FAT and a reduced quantity of fibres were observed compared to the control group. Comparison of the examined parameters between patients with glioblastoma and metastasis revealed statistically significant differences for MD (p < 0.001) regardless of the selected projection. CONCLUSIONS: The difference in MD (mean diffusivity) among patients with metastatic tumours may be related to an increased oedema zone.