Background: Maxillofacial trauma is one of the most common traumas with many complications and disabilities. Recognition of the trauma-related mechanisms is the key to early diagnosis and treatment. Objectives: The current study was aimed at assessing maxillofacial trauma in emergency department. Methods: The current cross sectional study was performed on 406 patients with maxillofacial trauma recruited from the emergency department (ED) of Shariati and Imam Khomeini hospitals from January 2014 to March 2015. Demographic data, etiology and mechanism of trauma as well as the type of maxillofacial fractures were recorded by the emergency medicine (EM) residents. Maxillofacial fractures, diagnosed by the computed tomography (CT) scan, were reported by the ED attending radiologist. Results: The current study evaluated 406 patients, 106 females (26.1%) and 300 males (73.9%), with maxillofacial trauma and the mean age of 29.95 ± 15.82 years. The leading causes of maxillofacial trauma were the road traffic accidents (RTA) (50.2%), followed by falling (20.0%) and assault (17.3%). Maxillofacial fractures were detected in 137 patients (33.7%) and mandibular fractures were the most common site (71.5%). The mean age of males was significantly higher than that of females. Some causes of maxillofacial trauma, such as assault and occupational accidents, were significantly common in males than females. The risk of maxillofacial fractures was significantly higher in the traumas caused by pedestrian-car accidents followed by falling and assault. Conclusions: In the current study population, the patterns of underlying causes of maxillofacial traumas were similar to other types of traumas mainly affected by socioeconomic status of the society. RTA was the main cause of maxillofacial trauma and males were affected more than females. Most of the current study patients were in the 3rd and 4th decades of life. Mandible was the site mostly involved in MF fractures.