The Ehlers-Danlos syndrome (EDs) is one of the most frequently inherited disorders of connective tissue. Type IV EDs, the arterial-ecchymotic type, is of concern to vascular surgeons because it is frequently associated with spontaneous catastrophic bleeding. This article summarizes our experience with five members of a family and reviews the 31 patients with type IV EDs described in the literature. The 22 male and 14 female patients had a mean age of 26 years. The 36 patients included 23 with easy "bruisability," 22 with hypermobility of their joints (especially the fingers), 13 with transparent skin, and 11 with excessive elasticity of the skin. The patients had 41 episodes of hemorrhage and 29 vascular surgical procedures. Twenty-nine of the patients had an aneurysm or a dissection, whereas eight patients had arteriovenous fistulas. Arteriography was associated with a complication rate of 67%. The prognosis for a patient with type IV EDs is poor; 44% die before surgery and 19% die during the operative period. Bleeding should be managed nonoperatively when possible. Fifty-one percent die before reaching 40 years of age. Arteriography should be avoided. The standard repair of aneurysms and perforations is unlikely to be successful because of marked vessel friability. Bleeding vessels should be repaired with buttressed sutures and no tension or should be ligated. Genetic counseling with assay of collagen production is recommended for family members.