We report on the occurrence of CSF rhinorrhea in a group of 17 patients harbouring macroprolactinomas who were treated with a dopamine agonist (DA, bromocriptine) alone or the combination of DA and transcranial operation. In 2 out of 17 cases shrinkage of tumour remnants during therapy with the oral or injectable form of bromocriptine was responsible for delayed occurrence of rhinorrhea. Operative procedures for successful closure of the fistulae were mandatory in both cases.