Noonan's syndrome is an eponymic designation that has been used during the last 8 years to describe a variable constellation of somatic and visceral congenital anomalies, which includes groups of patients previously referred to as male Turner's, female pseudo-Turner's and Bonnevie-Ullrich syndromes. It is now recognized that both sexes may show the stigmas of this condition and, unlike Turner's syndrome, there is no karyotype abnormality although there is often a familial pattern. The most commonly observed anomalies include webbing of the neck, hypertelorism, a shield-shaped chest and short stature. Congenital heart disease, principally pulmonary stenosis, and sexual infantilism often with cryptorchidism in the male subject are additional associated anomalies in this syndrome. Renal anomalies have been described rarely and usually consist of rotational errors, duplications and hydronephrosis. We report the first case of an infant who displayed many of the stigmas of Noonan's syndrome and also showed early evidence of frank renal failure secondary to renal dysplasia with cystic disease.