Essential arterial hypertension at children is a multifactorial pathology with a lot of risk factors producing a large spectrum of effects implied. Hyperhomocysteinemia is one of these factors that through the endothelial dysfunction shows the connection between arterial hypertension and atherosclerosis. Objective: estimation of the informativity of the homocysteine (Hct) as a marker of endothelial dysfunction at children with hypertension, overweight and obesity Matherial and methods: the investigation included 22 children with hypertention, obesity and overweight (average age 14,2 years old) devided in two groups acoording to the homocysteine values. Group I – 11 children with normal values of Hct. Group II – 11children with higher values of Hct. Serum concentration of of Hct was determined by ion-exchange liquid chromatography metod. The optimal level of Hct was comsideted 4-9 mkmol/l (NHANES 2003) Results: the analisis of groups of investigation revialed in group II aggravated family history: through AH at 10 children, obesity at 7, DM at 5 children, MI- at 3 and Stroke at 2 children, in comparision with the group I were aggravated family history was determined throut AH at 7 children, obesity at 5 and DM at 3. Simultaneously, the was found lipidic metabolism disordered determined by increase in total cholesterol and LDL cholesterol in group II. Conclusion: hyperhomocyteinemia through the endothelial dysfunction along with other factors (aggravated family history, dyslepidemia, etc) can be implied in the realization of the arterial hypertension at children with overweight and obesity.