We have correlated the clinical and histopathologic features of the eyes and central nervous system in a patient with Hallervorden-Spatz syndrome who died at age 11 years. The main ocular findings included degeneration of photoreceptors, marked thinning of the outer nuclear and outer plexiform layers, retinal gliosis, narrowing and obliteration of blood vessels with a perivascular cuffing of pigment cells, and degenerative changes in the retinal pigment epithelial cells with accumulation of melanolipofuscin. The positive findings in the brain included a symmetrical, partially destructive lesion of the globus pallidus, especially in its internal fibers and neurons; in addition, we noted gliosis, widely disseminated axonal spheroidal bodies, which were most numerous in the globus pallidus and pars reticulata, as well as deposits of iron. Our histopathologic findings implicate three possible mechanisms, namely, lipid peroxidation, a deficiency of fatty acid membrane components, and increased cGMP which, either singly or in combination, are responsible for a pathogenesis that is common to the eye and brain in Hallervorden-Spatz syndrome.