We report on a series of 48 patients, ages 14 to 20 year, with hypophyseal adenomas. Of these, 46 (96%) had secreting tumors, 3 had Cushing's disease, 9 had somatotrophinomas, and 34 (29 females and 5 males) had prolactinomas. Thirty cases were diagnosed as intrasellar adenomas (62%) while the remaining eighteen (38%) presented extrasellar expansion. Of 9 acromegalic patients, 7 had typical clinical and biochemical features 2 were exclusively prognatic with normal basal GH levels, but abnormal dynamic tests. Prolactinomas were noninvasive in women and faster growing and more extensive in men. Forty seven patients underwent surgery. Five of these required craniotomy and the rest approached through the sphenoidal bone (TSE). Remission was achieved in Cushing's disease, acromegaly, and female intrasellar prolactinomas. Larger tumors such as nonsecreting adenomas and male prolactinomas showed poor results after undergoing subtotal resections, with persistence of endocrinological disturbances. From our findings it appears that these tumors are aggressive in youth than in adults. Because there was a close relationship between tumor size, invasiveness, and the patients' final outcome, we conclude that early diagnosis and treatment is essential. Frequent complaints in adolescents such as irregular menses, retarded puberty, and growth disorders should be thoroughly investigated and not merely considered as transient or 'functional'.