Objective: This study investigates prevalence of children with behavioral disorders in primary schools in Tehran. Method: 1273 students were selected randomly, and their teachers completed Child Behavior Checklists (CBCL). Results: Results indicated that 20.3 percent of children have behavioral disorders based on clinical classification. Also 5.8 percent of students are borderline classification. The most frequent disorder in clinical classification is internalizing behavioral disorders and the least frequent disorder is anxiety. The most frequent problem in borderline group is depression and the lowest frequent problem is thinking problem.  Conclusion: The findings emphasize on the necessity of serious related interventions for these children.