This paper presents a retrospective review of jaw fractures sustained by 795 individuals in the county of Stockholm from 1978-80. The material comprised 904 mandibular and 249 maxillary fractures, a total of 1.153 fractures. The present part of the study concerns the relationship between etiologic factors and fracture location. Single fractures were noted in 43% of the mandibular fractures and in 4% of the maxillary fractures. The region most frequently fractured was the mandibular condyle (19% of all fractures). Violence was the etiologic in 42% of the total number of fractures and 47% of mandibular fractures. Compared to earlier reports, this seems to represent an increase over the last decades and probably reflects a general trend towards greater incidence of violence in society. Jaw fractures caused by traffic accidents accounted for 25% of all fractures and have decreased, probably as a result of the safety belt law of 1975 and better traffic security reforms. However, the severe Le Fort III fractures, combined with unconciousness and neurological injuries, are mainly the result of on traffic accidents. Falls accounted to 23% of the fractures, mostly localized to the mandible (81%).