Introduction: Separation Anxiety in children is a disorder that has a negative impact on social adjustment and peer relations which predicting psychiatric disorders in adolescence. If separation anxiety is not treated in childhood, the person will face a lot of problems in adulthood. Therefore the objective of this study was the effectiveness of Modular cognitive-behavioral therapy (MCBT) on reducing the symptoms of separation anxiety in children which is an effective treatment for separation anxiety.
Method: The design of the study was experimental, pre-test and post-test and follow up (two and three months) test with control group. Statistical population consisted of 388 preschool and first grade of primary school students in Qom that had separation anxiety symptoms while 76 students were selected as sample using multi-stage cluster sampling. Subjects were categorized randomly in two 33-students of 6 and 7 year old experimental and control groups. The experimental group received sessions of MCBT intervention. But no intervention was applied in control group. The Child Symptom Inventory (CSI) was used for data collection.
Results: ANOVA with repeated measure showed a significant difference between experimental and control groups. The results also indicated that the effects of gender and age and interaction of treatment method and gender and age were significant. 
Discussion and conclusion: Results of the study showed the effectiveness of Modular cognitive-behavioral therapy (MCBT) on reducing the symptoms of separation anxiety in 6 and 7 year old girls and as this therapy is more effective for the boys, we recommend this protocol for them.