The authors analyze their observations of 118 patients with hypophyseal microadenomas in 1990-1992. Forty-four patients had prolactinomas, 35 somatotropinomas, 29 corticotropinomas, and 10 mixed tumors of the hypophysis. Operative interventions via a transseptal approach developed by the authors were carried out in all the patients. Complications of such operations are analyzed and methods of their treatment presented. The results lead the authors to a conclusion that selective microsurgery should be a method of choice in the treatment of hypophyseal microadenomas.