Congenital heart defect (CHD) is present in half of the propositi with Noonan syndrome (NS). Aortic coarctation (AC) is rarely seen in NS, since only three male patients with NS and AC have been previously reported. On the other hand, AC is common in the Ull-rich-Turner syndrome, an aneuploidy disorder and not a mendelian syndrome. In order to evaluate if AC is truly rare in patients with NS, we reviewed our series of 184 propositi with NS and CHD. AC was diagnosed in 16 (8.7%) patients. There were 11 males and 5 females. All had normal chromosomes. Clinical characteristics of the patients are described. Familial occurrence was detected in one girl with NS and AC whose mother and sibs also had NS, but different form of CHDs. Thus, AC is more frequent in NS than previously reported.