Abstract: Mandible is the only mobile bone of the facial skeleton that plays a major role in mastication, speech and deglutition. Among the maxillofacial trauma, mandible is the high risk exponent. Fractures of the mandible comprise between 40 and 62% of all of facial fractures. The purpose of this study was to evaluate the epidemiology of mandibular fractures in Qazvin province (1995-2005). In this descriptive and cross sectional study the charts of 204 patients with 304 mandible fractures treated at Rajaii and Ghods hospital were retrospectively reviewed. Age, gender and job of patients, etiology of fracture, treatment methods, site of fracture, type of radiography and seasonal Variation were recorded and inserted into spss software. Two hundred and four patients with 304 sites of fractures had refered to Rajaii and Ghods hospital. Data showed that 76% of all of patients were men and 39.7% of all patients were in the 21-30 years old age group. Occupationally, most of patients were workers (20.8%). The most common site of fracture was in body (41.77%) followed by the condyle (14.8%) and symphysis (14.15%). Car accident (37.1%) and motor accident (17.5%) was responsible for the majority of the fractures. About 69.2% of the patients sustained only one fracture and 30.8% of them sustained >1 fracture site. In this study panoramic radiography had been used commonly (89/2%). About 34.3% of the patients sustained other facial fractures and 28.9% sustained other injuries. The most common signs and symptoms were pain and swelling. The majority of fractures (31.4%) had happened in the summer. The finding of this study, compared with similar studies reported in the literature, support the View that pattern of mandibular fractures Vary form one country to another and as such can provide a guide to design of programs towards prevention and treatment. It is recommended to obey the traffic rules and make the drivers to use safety devices during driving.