Myelin water fraction (MWF) maps are spatially noisy. Here we investigated a possible inherent spatial structure of MWF values along diffusion tensor imaging (DTI)-derived white matter (WM) tracts in 41 healthy subjects. Sixteen major fibre bundles were extracted and MWF was computed in sub-segments along each fibre tract and compared to surrounding voxels. MWF values were more spatially coherent along fibre bundles than elsewhere. The profile along the trajectory of fibre bundles estimated subjects’ age more accurately than tract-averaged MWF. We conclude that the spatial MWF distribution in WM consistently follows a distinct pattern along underlying fibre bundles across subjects.