Two siblings with Cockayne syndrome (CS) are described and the literature on the subject is briefly reviewed. Of particular interest were the unusual neuropathological findings in 1 of the patients. These included microcephaly, white matter atrophy with patchy loss of myelinated fibers, calcifications of the basal ganglia, occasional ferrugination of cerebral and cerebellar neurons, and severe cerebellar degeneration. Findings not previously reported in CS were proliferation of extremely bizarre astrocytes, neurofibrillary tnagles, and pigmentation of the globus pallidus. We conclude that brain involvement in CS is a result of primary degeneration in the central nervous system rather than being secondary to angiopathy or normal pressure hydrocephalus, as previously suggested.