Giant axonal neuropathy is a rare autosomal recessive childhood disorder characterized by a peripheral neuropathy and features of central nervous system involvement. Magnetic resonance imaging (MRI) of an 11-year-old boy with giant axonal neuropathy revealed high signal intensity in the white matter of the cerebrum and cerebellum on T,weighted imaging. An apparent diffusion coefficient map revealed increased apparent diffusion coefficient values in the periventricular, deep, and cerebellar white matter, basal ganglia, and thalamus. Increased apparent diffusion coefficient values in distinct locations suggest increased mobility of water molecules in the brain of a patient with giant axonal neuropathy. This finding could indicate a myelin disorder such as demyelination. Diffusion-weighted imaging should be performed to reveal apparent diffusion coefficient changes and determine brain involvement in patients with giant axonal neuropathy.