The aim of this study was to perform a systematic review of the etiology of nasal bone fractures (NBFs).In PubMed (500 titles) and Scopus (272), the search terms "nasal bone fracture" AND "etiology OR cause" were used. Among the 772 titles, 137 were duplicated and excluded. The 552 titles were excluded and 83 abstracts were read. Subsequently, 42 abstracts were excluded and 41 full articles providing data on etiologies of NBFs were reviewed. Finally, 26 papers were incorporated into this analysis.The causes of NBFs were different between adults and children. In adults, the most frequent causes were fights (36.3%), traffic accidents (20.8%), sports (15.3%), and falls (13.4%). In children, the most frequent causes were sports (59.3%), fights (10.8%), traffic accidents (8.3%), collisions (5.0%), and falls (3.3%). It is noticeable that fights, traffic accidents, and falls were more frequent in adults than in children, although sports and collisions were more frequent in children than in adults (P < 0.001). The causes of NBFs varied geographically. Fights were the most frequent cause in Asia (36.7%), South America (46.5%), and Europe (40.8%). In North America, however, traffic accidents were the most frequent cause (33.6%), followed by fights (20.7%) and sports (17.3%). Among the sports injuries, ball-related sports were the most frequent cause (84.2%). Fighting-related sports (6.4%) contributed to relatively small proportion of NBFs.In efforts to prevent NBFs in children, sports injuries should be primarily considered. Restraining devices such as seatbelts are needed to prevent NBFs caused by traffic accidents, especially in North America.