Turner's syndrome, a sex-chromosome abnormality, is often accompanied by cardiovascular disorders, such as coarctation of the aorta. We encountered a case of Turner's syndrome with meningioma and pituitary hyperplasia which resulted in death from dissection of the aorta. The patient was 36-year-old female who was diagnosed as having Turner's syndrome of mosaic-type at the age of 15. She had accepted sex-hormone replacement with estrogen and progesterone over 20 years. She lost consciousness and was transferred to our institute on June 20th, 1992. She was in shock but her condition began to improve after intensive treatment. CT scan revealed a calcified mass lesion at the left frontal convexity and a markedly enhanced round mass lesion at the suprasellar region. Angiography showed tumor stain of the suprasellar region fed by the posterior ethmoidal artery. These tumors were diagnosed as multiple meningiomas. She developed dyspnea on June 24th and chest X-ray showed right pleural fluid collection and cardiomegaly. This condition was diagnosed as congestive heart failure. Her condition was getting worse and she suffered abrupt cardiac arrest on June 28th. Autopsy revealed dissection of the aorta as the cause of death. The tumor of the convexity was meningioma, and the suprasellar lesion was diagnosed as pituitary hyperplasia. It is well known that frequent excess dose injection of estrogen can induce pituitary adenoma or hyperplasia in rats. In this case, the presence of pituitary hyperplasia was thought to be the result of long-term injection of estrogen.(ABSTRACT TRUNCATED AT 250 WORDS)