Despite numerous publications on COVID-19, at present, conceptual thinking of the problem is only at a nascence stage. Treatment of patients with ANCA-associated systemic vasculitis (AAV) during the COVID-19 pandemic is one of the relevant issues. Management of COVID-19 in AAV patients undergoing anti-B cell therapy with rituximab (RTM) requires comprehensive reasoning. This paper presents a case report about COVID-19 in a 59-year-old female with AAV in remission, who was previously treated with RTM. COVID-19 was diagnosed one month after the last RTM administration; there were moderate bilateral pneumonia, fever, and extrapulmonary manifestations, including lesions of the gastrointestinal tract and central nervous system. Clinical outcome of COVID-19 was favorable, with no signs of respiratory failure, and CRP values did not exceed 29 mg/l. We discuss published data on RTM use during COVID-19 pandemic and the effects of B cells and their depletion on the course and outcomes of COVID-19. Our case report and available published data do not allow to consider RTM therapy as a factor associated with severe course of COVID-19 and adverse outcome. Further analysis of COVID-19 in patients with AAV and other rheumatic diseases is important. © 2020 Ima-Press Publishing House. All rights reserved.