A 16-year-old girl with history of treated congenital mitral valve disease and signs of respiratory infection was admitted to our paediatric cardiology department. She was tested positive for severe acute respiratory syndrome coronavirus 2. Despite her severe pre-existing cardiac conditions with pulmonary hypertension, atrial arrhythmias and mitral valve stenosis, the infection did not lead to any cardiac or pulmonary deterioration. In adults, cardiac co-morbidities are known risk factors for a severe course of coronavirus disease 2019 infections. This case illustrates that in children even severe cardiac disease is not necessarily associated with a severe course of coronavirus disease 2019.