Objectives: To investigate the effects of Montelukast sodium combined with Budesonide aerosol on airway function and T lymphocytes in asthmatic children. Methods: The records of 86 pediatric asthma patients, treated in Huzhou Maternal and Child Health Hospital from February 2020 to March 2021, were studied retrospectively. Of them, 40 children received routine treatment + budesonide atomizer (Group-I), and 46 patients received routine treatment + budesonide atomizer + montelukast sodium (Group-II). The improvement in airway and lung function, and T-lymphocyte count in both groups after 3 months of corresponding treatment were analyzed. Results: After three months of treatment, expiratory flow rate (TEF) with the tidal volume of 25%, 50% and 75%, was significantly higher in Group-II than Group-I (P<0.05). CD8+ expression in Group-II was lower, and CD3+, CD4+ and CD4+/CD8+ were higher than those in Group-I (P<0.05). There was a significant difference in the levels of inflammatory factors between the two groups. The levels of IL-4, IL-5 and IFN-γ in Group-II were lower than those in Group-I (P<0.05). Conclusions: In the clinical treatment of asthmatic children, in combination with routine treatment, budesonide atomizer and montelukast sodium can effectively promote the improvement of airway function, regulate T lymphocytes levels, reduce inflammatory reaction and improve the total clinical curative effect. doi: https://doi.org/10.12669/pjms.38.5.5749 How to cite this:Jin W, Zhao Z, Zhou D. Effect of Montelukast sodium combined with Budesonide aerosol on airway function and T lymphocytes in asthmatic children. Pak J Med Sci. 2022;38(5):---------. doi: https://doi.org/10.12669/pjms.38.5.5749 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.