In order to know the exact incidence of oral complications due to the sublabial transsphenoidal approach, the authors meticulously heard the complaints of 46 patients, who had undergone the approach more than 3 months before. The incidence of the patients who had one or more complaints concerning the oral region was 52.2%. Dysesthesia of the upper lip was most frequent (37%), followed by upper lip pain (17.4%). These complaints were more marked in two patients who had undergone operations using the sublabial approach twice. Among the nine patients with dentures, the dentures had to be remade in three patients because of gigival atrophy several months after the use of the sublabial approach. With a view to overcoming these complications, the authors adapted the endonasal transsphenoidal approach in 13 patients. There was no inconvenience during surgery while this approach was being used, and there were no postoperative oral complications. Among three patients using dentures, there were none who needed remodeling of their dentures. In nine patients, the tension reducing incision was made in the bottom of the columella, which caused no cosmetic problem. Furthermore, the time consumed for approaching the sphenoid sinus was less than that required when using the sublabial approach. In conclusion, the following type of patient is believed to be an appropriate candidate for endonasal approach. A patient who has a relatively smaller sellar lesion and 1) An acromegalic patient whose nostril is relatively large, 2) An elderly patient using dentures, 3) A patient who has undergone previous transsphenoidal surgery, or 4) A patient whose columellar crease is hidden.(ABSTRACT TRUNCATED AT 250 WORDS)