A nine-year-old boy who exhibited mild proteinuria and severe renal dysfunction with short stature, mental retardation, retinitis pigmentosa, deafness, and intracranial calcification was presented. Clinical features of the patient were in the most part consistent with those of Cockayne's syndrome. On the renal biopsy, two-thirds of the glomeruli had fallen into global sclerosis. The remaining one-third showed thickening of the capillary walls and expansion of the mesangial matrix. Immunofluorescence study proved no significant deposition of immunoglobulins or complements. Electron microscopy revealed diffuse homogeneous thickening of the glomerular basement membrane. These histological findings were thought to be characteristic of the Cockayne's syndrome. Although the pathogenesis of Cockayne's syndrome is yet unknown, its renal lesions resembled those of an aged kidney, and a prematurely aged metabolic state was supposed as a principal cause of the disease.