Background: Bronchial asthma – is a chronic inflammatory disease of the respiratory tract and, like any chronic diseases, is characterized by involvement of the cardiovascular system in the pathological process, in particular, changes in the structure and function of the vascular endothelium and its role in the mechanisms of development and possible control of asthma has received considerable attention. The aim of our study was to determine the condition of the vascular endothelium in children with allergic bronchial asthma and to establish its impact on disease control. Material and methods: We examined 224 children with allergic asthma aged 6 to 17 years and 40 healthy children as a control group. All children were examined for the content of specific IgE (to confirm the allergic nature of asthma), homocysteine and VEGF (markers of endothelial dysfunction) and performed ultrasonography of the carotid and brachial arteries. Results: Children with asthma had specific IgE level higher than a healthy child in 19.12 times that confirms the allergic nature of asthma. Levels of homocysteine and VEGF were elevated (19.78 ± 0.46 mmol / l and 359.69 ± 14.26 pg / ml) compared with healthy children, and changed depending on the disease control. IMT in children with asthma (1.07 ± 0.02 mm) was significantly greater (p ≤ 0,001) in comparison with healthy children, and also varied with different variants of control. Speed indexes also changed due to deterioration of asthma control and depended on biochemical markers.