Background: Sublingual allergy immunotherapy (AIT) has been proven in meta-analyses to reduce both symptoms and medication use in asthma. Objective: To assess safety and efficacy of sublingual immunotherapy as add on treatment for 6 months on asthmatic children. Patients and Methods: In a randomized controlled study, we did this study at Department of Pediatrics at Zagazig University Hospitals, during the period from May 2019 to October 2019. It included 60 children who have mild to moderate persistent asthma symptoms according to (GINA guide lines 2015) confirmed with skin prick test for positive allergen sensitivity. Sixty asthmatic children were categorized in two groups (30 children, each): Group A: received only the standard treatment of asthma, Group B: received specific sublingual immunotherapy (SLIT) with the standard treatment of asthma. Results: After receiving SLIT treatment, total IgE was significantly lower than before treatment with improvement in pulmonary functional parameters in SLIT group. The SLIT group showed significant increase in control of asthma after six months of treatment with SLIT. There was a significant decrease in using medications after receiving SLIT group. Conclusion: Clinical evidence supports the use of SLIT for the treatment of asthma in children. Reduces allergic asthma symptoms and the need for medication.