INTRODUCTION: Computerized scanning technology has been in use for 30 years. Originally, it was called Computerized Axial Tomography or CAT. Today, with advances in miniaturization and computer software and a revolution in imaging, CAT scan technology has been moved from the hospital to the private dental office in the form of Cone Beam Computerized Tomography (CBCT), which will be an alternative radiographic study over the standard panoramic images. OBJECTIVES: This study evaluated the advantage of CBCT over panoramic X-ray in surgical removal of horizontally impacted mandibular third molars. MATERIALS AND METHODS: This study was conducted on twenty patients selected from the Outpatient Clinic of the Oral and Maxillofacial Surgery Department, Faculty of Dentistry, Alexandria University, diagnosed by horizontally impacted mandibular third molar class II position B. All patients were diagnosed clinically and radiographically. Patients were divided randomly in two groups, 10 patients were diagnosed preoperatively by CBCT film (study group) and the other 10 patients were diagnosed by panoramic radiographic film (control group). Intraoperative and postoperative evaluation was carried out to monitor postoperative pain, inferior alveolar nerve paresthesia, trismus and postoperative edema at 3 rd , 7 th and 15 th day. RESULTS: Patients in the study group experienced statistically significant less pain and less postoperative edema than those in the control group (p=0.05, and p=0.048 respectively). There was no statistically significant difference between the two groups regarding the trismus and no patients in both groups suffered of alveolar nerve paresthesia. Less postoperative pain was diagnosed in the study group than in the control group. No inferior alveolar nerve paresthesia was found in the two groups. There was no significant difference between the two groups regarding the trismus. Less postoperative edema was found in the study group than in the control group. CONCLUSIONS: CBCT showed higher specificity to the inferior alveolar nerve localization as compared to panoramic x-ray. Hence, it is recommended that CBCT imaging is to be considered included in the diagnostic work-up prior to surgical removal of deeply impacted third molars.