In many countries during COVID-19 pandemic the number of hospitalizations concerning diseases of the blood circulatory system decreased because patients began to avoid hospitals because of fear to catch. Other factors, including load of the state and private health care systems, could also have indirect effects. Research objective: studying of influence of a pandemic of COVID-19 on volumes and the result of hospitalization of patients with blood circulatory system diseases in the medical organizations of different forms of ownership Materials and methods: a source of information is the registers of accounts on compulsory health insurance provided by Territorial fund of obligatory medical insurance of the territorial subject of the Russian Federation with the population of 7.7 million people. The research captured the period from 2019 to 2021 analyzed data of 629511 cases of hospitalization (271848 cases in 2019, 183804 cases in 2020 and 173754 cases in 2021) in the round-the-clock hospital of patients with the diagnosis belonging to the class "Blood Circulatory System Diseases". For assessment of data retrieveds methods of a descriptive statistics, simple (unweighted) arithmetic-mean values, specific the weight of values of indicators were used. Results: volumes of specialized medical care in the conditions of the round-the-clock hospital at blood circulatory system diseases in the private medical organizations in perva year of a pandemic of COVID-19 decreased approximately on a quarter, then in 2021 increased to 90% of the volume of 2019. At the same time volumes of medical care in the state medical organizations at BSK decreased in three years almost by 40%. In private clinics patients with an idiopathic hypertensia are hospitalized three times less than in state, the share of cases of hospitalization in private clinics at coronary heart disease is higher. All-hospital lethality in private clinics was lower, than in state in 2019 – by 3.5 times, in 2020 – by 4.0 times, in 2021 – almost five times. Postoperative lethality in the state medical organizations is higher, than in private – in 2019 by 1.4 times, in 2020 – by 1.7 times, in 2021 – more than twice. The number of people (natural persons) to whom specialized medical care in the conditions of the round-the-clock hospital at BSK within one year is provided is twice less, than quantity of the cases of hospitalization considered and paid in the compulsory health insurance system for kliniko-statistical groups. Hospitalization frequency within a year of the same patient (natural person) averages 2.16 times in 2019, 1.83 times in 2020 and 1.78 times in 2021. And this phenomenon belongs generally to the state medical organizations. Outputs. At delivery of health care at BSK in the conditions of a pandemic the private medical organizations show important advantages before state - have more authentic statistics, more social and economically significant structure of hospitalization and also lower indicators of all-hospital and postoperative lethality. When planning volumes of medical care it is necessary to use the term "the finished hospitalization case" - the unit of measure of volume of specialized medical care in the conditions of the round-the-clock hospital containing all elements necessary for achievement of useful result of hospitalization.