The purpose of this study was to assess the incidence, location, and sizes of the accessory mental foramina in Bulgarian population using Cone-Beam Computed Tomography (CBCT). The CBCT records of 1400 Bulgarian patients were evaluated for Accessory Mental Foramina (AMF) by two expert radiologists familiar with CBCT interpretation. Their presence and location in relation to the Mental Foramen (MF) were assessed using axial, panoramic and cross-sectional 2-dimensional CBCT images. The long and short axes diameters of the AMF were also measured. Accessory mental foramina were observed in 3.86% of the patients: up to two foramina on one side, unilaterally presented in 94.4% of cases with AMF. Their location regarding MF was distally and inferiorly in 62.9%. In 35.5 % of cases with AMF the foramen was situated above the level of MF and therefore needs special attention before surgery. The mean inner long and short axis diameters were 1.5 mm (SD: 0.4 mm) and 1.2 mm (SD: 0.3 mm) respectively. The measurements ranged from 0.7-2.5 mm for the long axis and 0.7-2 mm for the short axis. Demonstration of AMF using CBCT can improve the surgery treatment planning in anterior part of the mandible and thus helps to avoid unwanted neurovascular damage and possible malpractice litigations. This is the first study about the incidence, location, and sizes of the accessory mental foramina in Bulgarian population and adds additional information regarding the Caucasian race.