Aim:Thesurgical success rates of microscopic and endoscopic transsphenoidalapproaches for treatment of hypophyseal adenomas have often been compared. However, little has been reported regarding sinonasal complications of these approaches. We comparedsinonasal complications after microscopic and endoscopic approaches for hypophyseal adenomas.Material and Methods:At our clinic, sinonasal complications occurred in in 31 patients who underwent microscopic transsphenoidal surgery between 2007 and 2014 and in 32 patients who underwent endoscopic transsphenoidal surgery between 2014 and 2016. We statistically compared the complications observed during endoscopic sinonasal examination performed by an otorhinolaryngologist.Results:Sinonasal pathology occurred in 22 of the 31 patients (70.9%) in the microscopy group (Group 1) and 19 of the 32 (59.3%) in the endoscopy group (Group 2). Of the 31 patients in Group 1, 13 had nasal septal perforation, 13 had nasal synechiae, three had anosmia, two had hyposmia and one had saddle nose deformity. In Group 2, no patient had nasal septal perforation, whereas eight had nasal synechiae, one had anosmia, 11 had hyposmia and four had infection.Conclusion:There were no statistically significant differences in sinonasal complications (e.g. synechiae, anosmia, deformity, and sinusitis) between the two groups. Although the perforation rate (especially for perforations in the middle portion of the septum) was statistically greater in Group 1 than in Group 2, the hyposmia rate was statistically greater in Group 2 than in Group 1.