Three patients with hyperprolactinemia (2 with pituitary tumors and 1 with a hypothalamic disturbance) underwent evaluation of their hypothalamic-pituitary-adrenal axis using ACTH, metyrapone and in one case repetitive insuün tolerance tests. With the exception of a suggestion of a slight increase in adrenal responsiveness to pharmacological doses of ACTH in one of the patients, there was no alteration in the adrenal responsiveness of the 3 patients evaluated. We conclude that hyperprolactinemia probably does not systematically modify the responsiveness of the hypothalamic-pituitary-adrenal axis