Introduction & Objective: Studies have shown the high prevalence rate of behavioral disorders in primary school students, which may underlie many complications and problems for the students and their families. The aim of this study was to determine the prevalence of behavioral disorders among primary school students.

 Materials & Methods: This is a cross sectional-descriptive study which have been done on 352 primary school students in Hamadan. Samples have been selected based on a multistage random sampling and Rutter behavioral disorder questionnaire (teacher form) was used for data collection. The data were analyzed by SPSS version 20 using chi-square.

Results: Our result showed that 16.1% of the participants suffered from behavioral disorders. The prevalence was more among the boys. Father's education and occupation, history of mental illness, parental divorce, and death of parents had significant relationships with the prevalence of behavioral disorders in these students.

Conclusion: According to the results, designing and implementing educational programs for the prevention and treatment of student's behavioral disorders appear to be essential.