We report the case of a 14-year-old male patient with no previous history of cardiovascular disease or thromboembolic episodes, admitted to our hospital with a severe form of COVID-19, in the 9th day of disease evolution, with acute respiratory and heart failure symptoms. Chest computer tomography showed bilateral multilobular ground-glass opacities, consolidations, and a sub segmental arterial branch thromboembolism. The echocardiography showed a dilated left ventricle with severely impaired left ventricular function (LVEF=30%) . Blood test showed extremely elevated NT pro-BNP (22 558 ng/L), inflammatory markers and D-dimers. The diagnosis of PIMS-TS, COVID-19 sepsis-related cardiomyopathy and pulmonary thromboembolism was made, with a favourable outcome under supportive treatment. Clinicians should be aware of this severe presentation of COVID-19 in children.