A flail chest can occur when cardiopulmonary resuscitation causes extensive rib fractures. Despite successful cardiopulmonary resuscitation, if the flail chest is not treated, the patient may not survive regardless of the correction of the primary condition that caused the cardiac arrest. Therefore, if flail chest persists despite proper conservative management to correct the flail chest, active surgical management is essential. We present a successful surgical treatment with pectus bar for a patient with flail chest, caused by extensive segmental rib fractures sustained during cardiopulmonary resuscitation for a massive pulmonary thromboembolism.