Cerebral white matter lesions are associated with poorer motor performances in the elderly, but the role of gray matter atrophy remains largely unknown. We investigated the cross-sectional relation between brain regional gray matter volumes and walking speed over 6m in the 3C-Dijon study, a large population-based study of community-dwelling persons aged 65 years and over (N=1623). Regional gray matter volumes were obtained using an automated anatomical labeling parcellation method. Multivariable analyses were performed using a semi-Bayes approach. After adjustment for potential confounders, persons who walked slower had a smaller volume of basal ganglia (regression coefficient [β]=0.054, standard error [SE]=0.028, p=0.05). In more detailed analyses, the volume of the caudate nucleus had a preponderant role on this association (β=0.049, SE=0.019, p=0.009), and walking speed decreased progressively with the volume of the caudate nucleus (p for linear trend<0.001). These results underline the role of gray matter subcortical structures, in particular of the caudate nucleus, in the age-related decline of motor performances among community-dwelling elderly subjects.