Growth responses to growth hormone (GH) treatment in Noonan syndrome are compared with those in short children with the other growth disorders. The responses in Noonan syndrome are much less than those in children with GH deficiency, a little less than those in children with non-endocrine short stature and almost the same as those in children with Turner syndrome. As it is speculated that GH induces puberty earlier that expected in Noonan Syndrome, the efficiency of GH treatment for final height in Noonan syndrome is not promising.