Cockayne syndrome (CS) is a rare autosomal recessive disorder characterized by growth retardation, senile-like appearance, loss of subcutaneous adipose tissue, photosensitive dermatitis, microcephaly, deafness, pigmentary degeneration of retina, disproportionately long limbs, skeletal malformations with knee contractures and neurologic abnormalities. This is a description of a three-year-old boy with typical features of Cockayne syndrome complicated with tetralogy of Fallot, pneumonia and hepato-splenomegaly. He had been suffering from frequent attacks of pneumonia and had been hospitalized for several times since birth. Tetralogy of Fallot was diagnosed under echocardiography study and he died suddenly in hospital during a mydriatic procedure in the Ophthalmologic Clinic.