A 31-year-old woman was referred to our hospital due to progressive dyspnea and a family history of pulmonary embolism. Multislice computed tomography depicted massive bilateral pulmonary embolism, and transesophageal echocardiography demonstrated a serpentine structure in both atria with the appearance of a thrombus. Furthermore, a highly mobile mass trapped in her patent foramen ovale was identified. She underwent emergency cardiac embolectomy and was discharged from our hospital with conventional anticoagulant therapy.