This study investigates the lateralized brain network responsible for visuospatial attention in humans. The authors used diffusion imaging tractography to examine the parieto-frontal connections in 20 right-handed subjects. They found a significant lateralization of the superior longitudinal fasciculus (SLF) II, which is associated with a greater deviation towards the left in the line bisection test and faster detection times in the left hemi-field. This lateralization suggests that the right hemisphere has a larger parieto-frontal network and is more specialized for visuospatial attention. The findings provide the first evidence of a bilateral parieto-frontal network in humans and suggest that hemispheric specialization is linked to an unbalanced speed of visuospatial processing. These results have implications for understanding the neuroanatomical basis of visuospatial attention and may help predict recovery in patients with lesions to these networks.This study investigates the lateralized brain network responsible for visuospatial attention in humans. The authors used diffusion imaging tractography to examine the parieto-frontal connections in 20 right-handed subjects. They found a significant lateralization of the superior longitudinal fasciculus (SLF) II, which is associated with a greater deviation towards the left in the line bisection test and faster detection times in the left hemi-field. This lateralization suggests that the right hemisphere has a larger parieto-frontal network and is more specialized for visuospatial attention. The findings provide the first evidence of a bilateral parieto-frontal network in humans and suggest that hemispheric specialization is linked to an unbalanced speed of visuospatial processing. These results have implications for understanding the neuroanatomical basis of visuospatial attention and may help predict recovery in patients with lesions to these networks.