In this report we describe an infant with WBS and congenital hypothyroidism, due to an important thyroid hypoplasia. The patient, a 1-month-old female, negative at primary neonatal thyroid screening, was referred to our hospital for dyspnea. Thyroid function tests showed a raised TSH (42 mIU/l; normal range 0.5-4 mIU/l) with a low FT(4) concentration (10.21 pmol/l; normal range: 10.29-24.45 pmol/l). Ultrasound examination of the neck showed a significant thyroid hypoplasia, whereas (99m)Tc-pertechnetate thyroid scintigraphy evidenced a thyroid gland in normal position, with reduced shape and overall weak fixation.