Social phobia is one of the most common disorders between adolescents and young adults .The aim of this study is to investigate the prevalence of social phobia in Abhar`s high school students, at the risk-period for developing social phobia, and its influencing factors . In this cross-sectional study, a total of 5526 high school students of both genders from Abhar were selected using a census sampling method. Participants were assessed for social phobia disorder using the Liebowit Questionnaire anonymously. Information was also collected for the some socio-demographics. Descriptive and inferential statistical methods with SPSS-17 used for data analysis. The prevalence of social phobia disorder was 17/2%. The study showed that sex (female); age- early age of adolescence; being single; from small family; with low educated and housekeeper mother; With a father who work in private job; Living in town; from family with average income  are associate with higher prevalence of disorder. Social phobia is highly prevalent among high school students in Abhar region. Study findings can help health decision makers implement a more comprehensive strategy in this community for interventions to promote mental health and prevent social phobia.