Regional cerebral blood flow was investigated in an 8-year-old boy with adrenoleukodystrophy by single photon emission computed tomography. The use of Tc-99m-hexamethylpropylene amine oxime revealed markedly reduced blood flow in the occipital, parietal, and temporal cortical gray matter, in addition to the anticipated reduction in white matter. The area with a decreased blood flow was more extensive than that detected by x-ray computed tomography.