Two women who presented with amenorrhea-galactorrhea and hyperprolactinemia associated with x-ray evidence of pituitary enlargement and suprasellar extension were found to have primary hypothyroidism. Resolution of the pituitary enlargement and galactorrhea occurred after thyroid hormone replacement. Both women spontaneously ovulated and conceived, and normal pregnancies resulted. Amenorrhea, galactorrhea, and/or pituitary enlargement may be the principal manifestations of primary hypothyroidism. In such patients, it is imperative that primary hypothyroidism be excluded before drug or surgical therapy for presumed prolactinoma is undertaken. When these findings are due to primary hypothyroidism, thyroid hormone replacement alone is adequate therapy.