Thrombolysis (1,500,000 IU streptokinase during 60 minutes and 500 mg acetylsalicylic acid was started in a 43-year-old woman with Turner's syndrome who had chest pain lasting for more than 45 min accompanied by ST elevations of 0.2 mV or more in leads II, III, aVF and V1-V5. Pain disappeared within an hour and the ST segments became isoelectric. Severe back and upper abdominal pain occurred 24 hours later. Computed tomography revealed an aortic dissection from the aortic valve to the descending aorta. Intraoperatively the rupture was found to extend to an apparently single left coronary ostium. The aortic valve was bicuspid and incompetent. After aortic valve replacement, resection of the ascending aorta and implantation of a vascular prosthesis the patient's condition gradually improved and she was discharged from hospital.