The 18q Deletion syndrome is seen in 1 out of 10 000 live births. The main features of the syndrome are short stature, hearing loss, hypotonia, mental retardation, endocrine disorders and autoimmunity. Here, we present 2 patients with this syndrome admitted to our clinic who were found to have insulin resistance in addition to mental retardation, short stature, autoimmune thyroiditis and hearing loss. The need to perform a karyogram analysis in cases presenting with these features is emphasized.