OBJECTIVE A retrospective review of management of patients with macroprolactinomas at Auckland Hospital 1974-93 to determine the efficacy of treatment. METHODS Patients were identified from departmental patient disease index records and treatment outcome assessed. RESULTS Thirty four patients (24 male, 10 female) were identified. The mean serum prolactin was 89,700mIU/L. Visual field defects were present in 20 and 24 were hypogonadal at presentation. Initial treatment was with bromocriptine (n = 24) or surgery (n = 7). Twelve medically treated patients were subsequently treated surgically (3 because of pituitary haemorrhage or infarction, nine because of slow or absent response to medication). Visual field improvement was similar in the medical and surgical groups and major treatment complications occurred in 3 of the medical and 3 of the surgical patients. Radiotherapy was given to 25 patients. Overall treatment responses over a mean follow up of 4 years were similar in surgically and medically treated patients. Overall only a third of patients had a normal serum prolactin at last follow up, pregnancy had occurred in 20% of potentially fertile patients and 35% were hypopituitary. CONCLUSIONS Bromocriptine is a satisfactory first line treatment for macroprolactinomas, but although treatment reduces tumour size and reverses field defects in 75% of cases only one third of patients achieve a normal prolactin over medium term follow up.