A 52-year-old male patient with the Ehlers-Danlos syndrome (familial hypermobility of the joints, hyperextensibility of the skin and atrophic cutaneous scars) was evaluated because of a mitral regurgitant murmur. Echocardiography demonstrated marked mitral valve prolapse of the both leaflets and vegetation-like thickening of the anterior leaflet of the mitral valve. Two-dimensional color flow mapping showed severe mitral regurgitation. This patient had also acrogeria-like facial appearance and very thin skin (subcutaneous veins were readily visible). He developed repeated rupture of radial, ulnar and middle cerebral arteries and expired. A histological section of the ruptured ulnar artery demonstrated no infectious process. In view of the joint hyperextensibility, very thin skin, characteristic facial appearance and the spontaneous occurrence of three successive ruptures of peripheral arteries, a diagnosis of Ehlers-Danlos syndrome (type IV) was made. Although mitral valve prolapse is reportedly common in type I, II and III Ehlers-Danlos syndrome, this report emphasizes that it may also occur in patients with type IV Ehlers-Danlos syndrome and the relevant literatures are reviewed.