A 20-year-old female was referred as a pituitary tumour with failure to grow. Primary hypothyroidism from the age of 8 had been diagnosed at the age of 11, when the patient was put on thyroid replacement therapy. Routine investigations showed normal anterior pituitary function, and confirmed the diagnosis of primary hypothyroidism. A needle biopsy of the pituitary gland revealed an empty fossa. The possible relation of the empty sella with the primary hypothyroidism is discussed. A chromosome anomaly, deletion of the short arm of an X chromosome, was found and its contribution to the delayed growth is discussed.