Twelve cases of histologically confirmed pituitary adenomas, classified as Grade 1 to 2B, underwent transsphenoidal surgery. Sixty-six percent of the tumors were functioning. Four of the tumors were microadenomas and 8 were macroadenomas, 5 of which had supresellar extensions. There was no operative mortality. The lone morbidity was that of a chronic subdural hematoma that was succesfully evacuated. The procedure provided a more rapid and direct access to the pituitary gland, better differentiation of the tumor from the gland, less trauma to the patient and less probability of injury to nearby structures. Visual function improvement and endocrinologic care rates were excellent.