Noonan syndrome (NS) belongs to one of the most frequent genetic disorders with autosomal dominant pattern of inheritance. The main symptoms of NS are short stature, congenital heart defects, thorax deformities and specific dysmorphic features: hypertelorism, low set ears. short and wide neck, wide spaced nipples. The clinical picture ofNS changes with the age, which impedes the proper diagnosis in adults. We present two familial cases of Noonan syndrome with mutated PTPN11 gene in probands and one of their parents and siblings. We analyzed clinical features with regards to NS diagnostic criteria.