Device-related thrombosis and device-related endocarditis after atrial septal defect (ASD) transcatheter closure are extremely rare. It is known that COVID-19 infection could lead to a thrombotic microangiopathy-like phenomenon. We present the case of a 14-year-old female who developed fever and was found to have a thrombus on the right atrial side of the ASD closure device weeks after an asymptomatic COVID-19 infection and negative COVID-19 test 2 days before transcatheter ASD closure. Although there is no certainty that the thrombus was related to the prior COVID-19 infection, the possibility of an ongoing COVID-19-related hypercoagulable state should be entertained.