Although cardiac contusions are common, cardiac rupture is an uncommon sequela of blunt chest trauma. The mortality rate associated with cardiac rupture is very high, and patients usually do not survive long enough to reach the hospital. We report a 66-year-old man with a history of coronary artery bypass grafting 15 years previously, who was involved in a traffic accident and experienced multiple trauma, including a small contained rupture of the right ventricular outflow tract. He survived, and a false aneurysm developed at the site of the rupture within the next 6 months. The patient then underwent a cardiac operation, and the aneurysm was successfully resected. The intraoperative and postoperative courses were uneventful. In this case, the previous cardiac operation with the resulting pericardial adhesions proved to be lifesaving.