Introduction. Patients with chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD) are increasingly found in the clinical practice. The comorbidity of CHF and COPD promotes high mortality in such patients. Therapy that is prescribed to patients with CHF and COPD may not always have a positive effect on the condition of blood vessels. In this regard, researchers began to pay attention to drugs that have a beneficial effect on blood vessels, without worsening the course of CHF and COPD, one of which is meldonium.The purpose of the study. To study the effect of meldonium as part of complex therapy on arterial stiffness and microcirculation in patients with CHF and COPD.Materials and methods. The open randomized study included 60 patients with CHF IIA stage, II–III functional class (clinical recommendations of RKO, OSSN 2020) and COPD of the I–III degree of airflow restriction (classification GОLD 2021) without exacerbation. The patients were divided into 2 groups: the 1st group – the main group (n = 30) with CHF and COPD, which was prescribed meldonium as part of complex therapy at a dosage of 1000 mg/day, the 2nd group – the control group (n = 30) was on therapy only with basic drugs of CHF and COPD. The observation period is 12 weeks.Results. As a result of 12 weeks of therapy with the inclusion of meldonium in the complex therapy of patients with CHF and COPD, a decrease in the stiffness of the main arteries, an improvement in the regulation and parameters of microcirculation, an increase in the frequency of occurrence of the normocirculatory type of microcirculation were noted.Conclusions. A significant useful effect of complex therapy with the inclusion of meldonium on the condition of arterial stiffness and microcirculation in patients with CHF and COPD has been established, which makes it possible to recommend the use of meldonium in this category of patients.