<p>The pterional approach remains a cornerstone in skull base neurosurgery, offering extensive access to the anterior and middle cranial fossae. Various surgical modifications have been proposed to optimize surgical exposure. One modification is the interfascial temporalis flap technique, which seeks to overcome the limitations of the traditional myocutaneous flap. This study aims to evaluate whether the enhanced exposure provided by the interfascial technique is associated with increased delayed postoperative temporalis muscle atrophy compared to the myocutaneous flap in patients undergoing pterional craniotomy. A retrospective analysis of 66 patients was conducted. Of these, 36 underwent muscle mobilization using the interfascial flap and 30 with the myocutaneous flap. Temporalis muscle volume was assessed at 4–9 months postoperatively using thin-slice axial CT scans and 3D Slicer software. The percentage of muscle preservation was defined as the volume ratio of the operated side to the contralateral non-operated side, multiplied by 100. The interfascial group showed higher muscle preservation (mean 76.6%) compared to the myocutaneous group (mean 69.0%) (<i>p</i> = 0.01). No significant differences were found in demographic or clinical parameters, including age, ICU stay, follow-up imaging time, or hospitalization. Importantly, no cases of permanent frontal branch palsy were identified in either group at the 3-month follow-up. Interfascial temporalis flap technique is associated with better temporalis muscle preservation and less atrophy compared to the myocutaneous flap. In other words, increased exposure provided by interfascial temporalis flap doesn’t come at the expense of late temporalis muscle atrophy.</p>