We report the case of a 35-year-old man who had a transient ischemic cerebral attack and then underwent a percutaneous closure of the patent foramen ovale (PFO) with a Cardiastar device. One year later, the patient developed a cardiac tamponade due to an important hemorrhagic pericardial effusion. Transoesophageal echocardiography showed that one of the struts had impinged on the aortic root in the region adjacent to the transverse pericardial sinus. Therefore, we speculated that the strut had passed through the aortic wall by slow erosion, leading to the pericardial effusion. Cardiac CT and subsequent surgery confirmed the perforation of the left atrial roof and the aortic root by two struts of the device. This is the first reported case of late cardiac tamponade and underscores the importance of long-term follow-up after PFO closure device implantation.