We have compared three treatments of congenital adrenal hyperplasia (CAH) for their effect on physical development. Thirteen girls and two boys with CAH due to 21-hydroxylase deficiency were treated with three different treatments, hydrocortisone (HC), dexamethasone (DXM) and cyproterone acetate (CA). The results showed that height growth was better with HC and CA than DXM, and bone excessive maturation was more suppressed with DXM and CA than HC. A dose-dependent relationship was revealed between body weight and dose of HC. Iatrogenic obesity was found in 42.9% and 38.1% of the patients treated with DXM and HC, but none of the patients treated with CA did became obese. Physical growth was better with CA treatment than HC or DXM treatment, but CA may have a suppressive effect on the pituitary-adrenal axis observed carefully, especially on prepubertal and pubertal cases.