A sporadic case of a young woman with Ehlers-Danlos syndrome (EDS) type IV is described. Multiple aneurysms of medium-sized arteries were noted. Histological study revealed deposition of acid mucopolysaccharides in the media of major arteries and in the intima of smaller arteries with intimal thickening. Systemic changes related to stenosis were observed in arteries more than 100 microns in diameter. Histologic study revealed hyperplasia of adipocytes in the submucosal layer of the intestines and the trachea, and fibrosis of Langerhans' islets of the pancreas. Typical signs for EDS such as skin hyperelasticity and joint hypermobility, and positive family history were not present. However, type III collagen was not detected on frozen sections from either the skin or the anterior cerebral artery by immunohistochemical quantification. Thus, it was concluded that the present case is a variant of EDS.