The combination of amenorrhea, galactorrhea, and hyperprolactinemia in a young woman usually suggests a prolactin-secreting adenoma of the anterior pituitary gland. Primary thyroid failure may also be associated with hyperprolactinemia, galactorrhea and suprasellar enlargement of the pituitary. 2 women, aged 23 and 28, respectively, presented with the latter syndrome. 1 was even a candidate for neurosurgery. However, because serum TSH and prolactin levels were elevated, thyroxin replacement therapy was started. It induced normal menses, galactorrhea stopped, and in follow-up CT scans the pituitary become normal in size. Hyperprolactinemia with secondary hypothyroidism, caused by a pituitary adenoma, must be distinguished from primary hypothyroidism, also a cause of hyperprolactinemia.