Computed tomography (CT) in a 34-year-old woman with Hallervorden-Spatz disease (established on the basis of clinicopathologic findings in a sister, and a typical clinical course) showed severe diffuse cerebral atrophy and ventricular enlargement. Ratios between the intercaudate distance and the width of the frontal horns (FH:CC) or the outer tables of the skull (CC:OTcc) exceeded those found in patients with Huntington disease. CT may be helpful diagnostically in progressive cerebral disorders of late childhood or adolescence.