The purpose of this study was to evaluate changes in brain activity during voluntary walking in normal subjects using technetium-99m-hexamethyl-propyleneamine oxime single photon emission computed tomography. This study included 14 normal subjects. Statistical parametric mapping analysis revealed that the supplementary motor area, medial primary sensorimotor area, the striatum, the cerebellar vermis and the visual cortex were activated. These results suggested that the cerebral cortices controlling motor functions, visual cortex, basal ganglia and the cerebellum might be involved in the bipedal locomotor activities in humans.