The infra-orbital foramen (IOF), due to the infra-orbital artery, vein and nerve which pass through it, is an important anatomic landmark and its location needs to be known for the maxillofacial interventions. However, there might be an accessory branch of the infra-orbital nerve that are taken care during these interventions. This accessory nerve passes through the accessory infra-orbital foramen (AIOF). In the current study, in order to perform anatomic and morphometric analyses of AIOF, 112 skulls have been used. Appearance and frequency of AIOF, its direction with respect to IOF have been determined and distances to certain specified points have been measured by a digital caliper. It has been determined that the frequency of AIOF is 7% and often locates on the left (66.5%) and in the superomedial of IOF (93.3%). The average longest diameter of AIOF has been measured as 1.93 mm and the shortest diameter has been measured as 1.56 mm. It has been found that AIOF locates 22.18 mm away from the mid-line, 39.92 mm away from the supraorbital foramen/ the supraorbital notch, 21.95 mm away from the lower end of the nasomaxillary suture, 34.45 mm away from the lower end of the alveolar juga of the canines, 5.61 mm away from the infra-orbital margin, 3.95 mm away from IOF at the same side and 51.18 mm away from IOF at the opposite side. AIOF should be taken into consideration especially in oral and maxillofacial interventions on the left side of face.