BACKGROUND This study aimed to retrospectively analyze patient clinical data to investigate the effects of computed tomography (CT) reconstruction and the measurement of abnormal structures in the endonasal sphenoidal sinus approach on the operative effects in patients undergoing pituitary adenoma resection. MATERIAL AND METHODS The records of 53 patients who underwent pituitary adenoma resection via the endonasal transsphenoidal approach in the Neurosurgery Department of Tai'an City Central Hospital from December 2010 to June 2016 were analyzed retrospectively. All cases showed anatomical abnormalities in the endonasal transsphenoidal approach that were detected by conventional CT scans. The clinical data of the patients were reviewed. After review, 26 patients who underwent preoperative CT reconstruction and measurement of abnormal structures before surgery were included in the observation group (CT reconstruction group), and 27 patients who did not undergo CT reconstruction and measurement of abnormal structures were included in the control group. Data on intraoperative blood loss, surgical time, hospital stay, and postoperative complications were collected to assess the quality of the surgery. RESULTS Compared with the control group, the observation group showed less blood loss (p<0.001), a shorter operation time (p<0.001), fewer postoperative complications (p<0.001), and a shorter hospital stay (p<0.001). CONCLUSIONS Preoperative CT reconstruction and measurement of abnormal structures in patients undergoing pituitary adenoma resection by the endonasal transsphenoidal approach can improve operative quality and reduce complications.