The use of the rigid endoscope has been evaluated during transsphenoidal microsurgery of 10 pituitary adenomas: three were prolactin-secreting adenomas; five growth hormone (GH)-secreting adenomas; and two without evidence of known endocrine activity. The use of the endoscope allowed close inspection and differentiation between tumour tissue and glandular remains. This resulted in microdissection of the tumour with maximum preservation of pituitary function. The angled view of the telescope helped total gross removal of tumour tissue from the less accessible supra- and para-sella extensions. More cases and a longer period of follow-up are necessary to provide long-term results.