Almost all children are anxious at one time or another because of separation from a parent or primary caregiver. However, children may develop separation anxiety disorder when they exhibit inappropriate and excessive functioning-impairing anxiety when their parents are away from home and separated for a period of more than 4 weeks. Younger children may have recurring nightmares of being kidnapped, harmed, or having a parent die; older children fear a car accident if their family leaves them, or that they have been abducted, etc. They show depressed moods and are reluctant to go to school, and even if they do go reluctantly, they often cry and sometimes experience headaches and abdominal pain. Refusal to go to school is very common among children with separation anxiety disorder. Of course, there are various reasons for reluctance and refusal to go to school, and separation anxiety is only one of them. The main signs of separation anxiety are: 1) excessive anxiety about being separated from family members, which is not appropriate for the child’s developmental level; 2) persistent and excessive fear that an unfortunate event will separate them from their primary attachment; and 3) chronic reluctance to go to school or go elsewhere because of fear of leaving parents. The prevalence of separation anxiety disorder is higher in children than in adolescents, similar in both sexes, and can begin before school age, but mostly at age 7-8. The prevalence is 3-4% in children and 1% in adolescents. 1. The etiology is often related to biosocial and learning factors. 2. These children often have difficulty sleeping. 3. The course of the disease is related to the prognosis and the age of onset, duration of symptoms, and co-morbidity, and children who can insist on going to school have a better prognosis. 4, treatment is based on comprehensive treatment, mainly including psychotherapy, medication, parental education, etc.. Parents should encourage their children to go to school. 5.When psychotherapy alone is not enough, medication can be helpful.