We experienced a case of a cesarean section of a 32-year-old female with an thoracic aortic dissection under general anesthesia. An aortic dissection in pregnancy is rare but a potentially catastrophic occurrence. There is a poor prognosis if an aortic dissection occurs in pregnancy in the third trimester. The importance in anesthetic management of these patients should prevent any hypertension in response to intubation and surgery with appropriate preoperative care and monitoring.