Atrial septal defect (ASD) is the one of the most common congenital cardiac diseases. Percutaneous device closure of the ASD has developed as an alternative to traditional surgical closure with a similar outcome, decreased surgical trauma, and shorter hospital stay. However, several complications have been reported. We now report a rare complication of late severe mitral insufficiency (MI) after a successful closure of a secundum ASD with an Amplatzer device. The potential mechanisms may be the continual traction of the oversized mismatched device on the root of the mitral annulus and the insufficient rim to the mitral annulus. The patient was sent for a surgical operation to remove the device, and the defect was closed. No MI was found at the one-year follow-up.