Cockayne syndrome is a rare autosomal recessive disorder of childhood characterized by cachectic dwarfism with senile-like appearance, mental retardation, photosensitive dermatitis, loss of adipose tissue, pigmentary degeneration of retina, microcephaly, deafness, skeletal and neurologic abnormalities. We describe here an 18 year old boy with Cockayne syndrome who had, in addition to the typical features of the disorder, fasting hyperinsulinemia and growth hormone deficiency.