SUMMARYA 38–year‐old amenorrhoeic woman suffering from a prolactin (PRL) secreting adenoma, which had suprasellar extension as shown by carotid angiography and computed axial tomography (CAT), was treated with a dopamine agonist (lisuride). PRL levels were lowered and after 1 year of treatment CAT showed a marked reduction of the tumour size. After 2 years of treatment menstruation returned and CAT demonstrated a further reduction of the adenomatous tissue. This study supports the suggestion that dopamine agonists possess an anti‐pro‐liferative effect on tumoural lactotrophic cells of