A nasoseptal flap is used to reconstruct defects in the skull base when cerebrospinal fluid (CSF) leaks after the endoscopic endonasal transsphenoidal approach (EETSA). We evaluated the usefulness of elevating bilateral nasoseptal flaps with the EETSA. Sixty-seven patients (71 procedures, including 4 revisions) underwent the EETSA with bilateral nasoseptal flap elevation. We retrospectively reviewed patients' medical records, including demographic data, surgical procedures, outcomes, and complications. The entire sellar floor was exposed after elevating bilateral nasoseptal flaps. We reconstructed the defect using a right nasoseptal flap in 14 cases with intraoperative CSF leakage. The denuded sphenoidal sinus was covered with a left nasoseptal flap in 13 cases with excessive loss of sphenoidal sinus mucosa. Unused flaps (57 right flaps and 58 left flaps) were repositioned in the original sites. No postoperative CSF leak occurred. All sphenoidal sinuses covered with the left nasoseptal flap healed well without excessive crust. Two patients experienced immediate postoperative bleeding. Septal perforation occurred in 1 patient who underwent a revision operation. Bilateral nasoseptal flap elevation provided good exposure of the sellar floor with the EETSA. The nasoseptal flap could be used to reconstruct the defect after the EETSA and to cover the denuded sphenoidal sinus. The unused flaps could be repositioned in their original sites to minimize the septal defect and could be reused in revision surgery. We suggest that elevating bilateral nasoseptal flaps is a useful surgical technique in a variety of settings with the EETSA.