Background: Subclinical hypothyroidism (SH) is most commonly an early stage of hypothyroidism. Although the condition may resolve or remain unchanged, within a few years in some patients overt hypothyroidism develops, with low free T4 levels as well as a raised thyroid stimulating hormone (TSH) level. Patients with SH may have subtle hypothyroid symptoms with mild abnormalities of serum lipoproteins and cardiac functions. L-thyroxine in a dosage that maintains serum TSH levels within the normal range is the preferred therapy in these patients. Although short stature is a well-known clinical sign of overt hypothyroidism, the effect of SH in growth is not well established. The aim of the present study is to show the effect of treatment on height in these patients.