Introduction: SARS-CoV-2 infection may predispose patients to thrombotic disease. Patients with COVID-19 pneumonia who are receiving non-vitamin K antagonists or direct oral anticoagulants for chronic disease are usually switched to heparin treatment during hospitalization. However, information about the most appropriate antithrombotic therapy after the acute infection phase is lacking. Case Description: We report the case of a patient with chronic atrial fibrillation who was recently hospitalized for severe COVID-19 pneumonia. Four weeks after discharge he experienced an episode of an acute pulmonary embolism while on rivaroxaban therapy with adequate drug plasma levels, and in the absence of strong predisposing risk factors. Conclusion: This case highlights the risk of thrombotic complications after COVID-19 infection, raises some concern about their underlying mechanisms, and supports the use of effective anti-thrombotic therapy. LEARNING POINTS: COVID-19 infection is associated with frequent thrombotic events.A pro-coagulative status could be triggered by the persistent inflammatory phase of the infection despite anticoagulation.Adequate antithrombotic therapy is necessary for the prevention of acute and later thrombotic complications and needs close monitoring.