Backgrounds and Objective: Using helmets reduces the rate of death and head injury in accidents. No study has yet been done in Iran to estimate the rate of helmet use. Hence، this study is to survey the rate of helmet use and its related factors among motorcyclists in Kerman city.Materials and Methods: In this cross sectionalstudy data collection was done by two people، an observer and a person completeing the check list، in winter and summer of 2012، on holidays and work days، morning and afternoon، main streets، bystreets and freeways. Descriptive and analytical analysis (the Chi - Square and Regression logistic tests) were done in SPSS16.Results: Among 2880 motorcyclists، 324 people (11.2%) used helmets. This number was significantly less on holidays; (p<0.001) and higher in winter in comparison to summer; (p<0.001). There was not a significant difference among the main streets، bystreets and freeways. (p=0.206).Conclusion: Comparing this research to similar statistics in different countries shows a low rate of helmet use in Iran. In addition to legislation exertion، more education and planning for increasing the use of helmets must be performed.