External pituitary radiotherapy is sufficiently free of serious side effects to argue for it being a first choice of treatment in acromegaly provided it is therapeutically effective. Of 28 acromegalic patients who had received external radio-therapy to the pituitary gland, 22 or 78% had normal or very near normal basal serum growth hormone levels. This experience compares with a recent report of favorable results with conventional radiation therapy but contrasts with experience from some centers. Disparate results between centers argue for analysis of factors which may contribute to varying therapy results. Some of these factors, as well as the comparative morbidity associated with external radiotherapy and other forms of treatment in acromegaly, are reviewed and considered. External radiation therapy of the pituitary in acromegaly continues to represent appropriate therapy in this disease.