We present eight cases with short stature, pituitary hyperplasia, and hypothyroidism. Pituitary hyperplasia due to primary hypothyroidism was diagnosed on the basis of clinical manifestations, endocrine examination and MRI. After 2 to 6 months of L-thyroxine replacement therapy, the signs of hypothyroidism disappeared; free triiodothyronine, free thyroxine, thyrotropin and prolactin became normal; and pituitary enlargement regressed. In two children, the growth rate remained low when treated with L-thyroxine, but with additional recombinant human growth hormone (rhGH), the height increased by 11 cm per year. No recurrence of lesions was found on follow-up.