Comparison of Self-Report, Peer-Report, and Principal-Report in Bullying Victimization and Perpetration Among Iranian Students

background: bullying among adolescences is known as a public health abnormality and studying the prevalence of bullying behaviors using different methods of data gathering can help researchers in surveillance and planning preventions. objectives: the objective of this study was to compare the prevalence of perpetration and victimization of bullying reported by self-report, peer-report, and principle-report. methods: in this cross-sectional study that was conducted in 2017 - 2018, a total of 1,540 students from 42 schools throughout mazandaran province completed self- and peer-report questionnaires and 42 principals of 42 schools completed a principal-report questionnaire. the chi-square test was used to compare the prevalence of victimization and perpetration of bullying with self-report, peer-report, and principal-report methods across gender, school types and grade levels. results: the prevalence of bullies and victims in self-, peer-, and principal-report methods were different (20.2% as victim and 7.8% as a bully for self-report, 9.4% as victim and 8.9% as a bully for peer-report, and 4.3% as victim and 3.1% as a bully for principal-report). conclusions: this study showed the discrepancy in the prevalence of perpetration and victimization of bullying reported in three measurement methods (self-, peer-, and principal-report) in iranian schools and suggests the use of multiple assessment methods for bullying behaviors.