We describe a 32-year-old pregnant woman at 31 + 6 weeks of gestation who presented to a tertiary-care hospital with headache and back pain. She was found to have a sign of tear about 1.3 cm away from the aortic valve, and the torn intima extended upward to the ascending aorta and the descending part of the aortic arch. She delivered a live male neonate via cesarean delivery. She had a history of hypertension with oral Labetalol 50 mg twice times daily. At the very beginning of the onset, physicians in the emergency room wouldn’t be aware of the symptoms of aortic dissections, as well as atypical presentations which include anterior chest pain or chest pain radiating to the back. She was only received anti-hypertension management, until her symptoms of back pain aggravated, and an aortic dissection was confirmed by ultrasound and CT angiography. Then she received a mechanical aortic valve replacement. After 51 days of treatment, she was discharged and recovered without any complications. Aortic dissection in pregnancy is a rare disease. We recommend transthoracic echocardiography every 1 to 2 months to monitor the diameter of the ascending aorta during pregnancy in which patients with hypertension problems or other risk factors of aneurysm and perform the CT angiography scan to confirm aortic dissection in a pregnant or postpartum woman with suspicious pain symptoms. It is essential that multidisciplinary approach in which teams must urgently collaborate to ensure the protection life of both mother and baby.