A 26-year old symptom-free woman was admitted to our Clinic for evaluation of hyperprolactinemia. The patient, who had normal menstrual cycles, was found accidentally to have a cystic adnexal mass and was placed on oral contraceptives (OC) for 3 months. During the first OC-cycle a bilateral breast nipple discharge was noticed and an elevated serum prolactin (PRL) was detected (2.7 nmol/l). The OC was discontinued and bromocriptine therapy was started. Serum PRL levels were restored and spontaneous menses resumed. The Pituitary magnetic resonance imaging (MRI), the anterior pituitary function, assessed by dynamic tests, and the thyroid hormone levels were normal. Upon bromocriptine discontinuation, PRL levels increased to 13.8 nmol/l. Poly-ethylene-glycol precipitation of the patient's serum, in two consecutive measurements, demonstrated the presence of macroprolactinemia. Since the patient was asymptomatic, a dopamine agonist was not resumed. Macroprolactinemia is characterized by most authors, as a benign condition with no clinical implications. However, a number of investigators challenge this view, suggesting that in some cases mild symptomatology is present possibly requiring therapeutic intervention.