The Smith-Lemli-Opitz syndrome is characterized by mental retardation, hypotonia, facial dysmorphism and abnormalities of the limbs, genitalia and kidneys. Since the latter 2 features have not been emphasized in the urological literature, the experience from the institution at which the syndrome was first described is reviewed and an illustrative case is reported. Upper urinary tract abnormalities were noted in 57 per cent and genital abnormalities in 71 per cent of the children evaluated.