Cognitive impairment and gait disturbances are the most frequent clinical findings in patients with leukoaraiosis (LA). Corpus callosum (CC) atrophy has been associated with dementia in patients with LA, as well as with gait disturbances in patients with normal pressure hydrocephalus. We investigated, in patients with LA, the possible association between gait impairment and CC atrophy, taking into account cognitive deficits and the other brain lesions commonly present in these patients. Thirty patients (M:F=21:9; mean age 72.5+/-6.3 years) with gait disturbances and brain CT images consistent with LA underwent an assessment of gait and a cognitive assessment of global and selective functions. Magnetic resonance imaging (MRI) was used to measure thickness and area of the CC, total LA volume, lacunar infarcts and size of lateral ventricles. We examined the effect of every MRI change on each performance measure. Reduction of CC thickness, particularly that of the anterior segment, had a significant effect on severity of gait impairment, as measured using the gait scale's score. It was independent of any other brain changes revealed by MRI, including LA. An independent, significant association was also found between CC area and the Left Hand Praxis test results. In patients with LA, CC atrophy is associated with gait impairment independently of LA and other brain abnormalities usually present in these patients.