A group of 17 strictly intrasellar prolactin-secreting pituitary adenomas between 2 and 9 mm in size was examined by computed tomography before and after bromocriptine therapy of 3 months to 1 year duration. These findings were compared with clinical and biological data. Bromocriptine therapy was effective clinically and biologically in 14 of the 17 cases. Of the 15 intrasellar adenomas in nonpregnant patients treated with bromocriptine, six disappeared completely with normalization of the pituitary appearance, five decreased approximately 50% in volume (three showed an increase in density, two a decrease), and four remained unchanged in size (two showed increased density, two showed very low densities).