Purpose and objectives: Vitamin D deficiency is associated with many diseases that attack the respiratory tract. Bronchial asthma is one of them. The purpose of this study is to evaluate whether there is a connection between overweight and low levels of Vitamin D in serum in children diagnosed with bronchial asthma. Material and Method: This study was conducted at the University Clinical Center, Department of Pediatrics, Pristina, Kosovo. The research project started in September 2019 and ended in May 2020. In obese children diagnosed with bronchial asthma, vitamin D levels in serum were evaluated.The study was carried out in the time periods in which we expected fewer sunny days, autumn, winter, spring. The research includes the time period: September 2019 to April 30, 2020. The level of 25(OH)D in the serum is considered the best marker for determining the metabolic status of vitamin D. The analyzes were done with the Electrochemiluminescence (ECL) Roche Cobas E411R measuring method! Results: obese children diagnosed with bronchial asthma based on vitamin D level were divided into three groups: below < 30nmol/L (deficient value); 8 children with vitamin D values from 30-50 nmol/L (insufficient value); 2 children with vitamin D values above > 50 nmol/L (normal value). Conclusion: Vitamin D deficiency was significantly higher in obese patients (57.9%) and overweight patients (55.6%), while the structure of vitamin D deficiency cases was lower in the group with normal BMI (28 .6%).