The Ehlers-Danlos syndrome is a relatively common heritable disorder of connective tissue. The cardinal features are cutaneous hyperextensibility, joint hypermobility, bleeding diathesis, and tissue fragility, and these features lead to a large variety of additional manifestations. Of the eight presently described types, four varieties have been found to be caused by defects in the biogenesis of collagen, the major structural protein of the body. Consideration of the clinical features and probable mode of inheritance will permit subclassification of many patients into specific types, and biochemical confirmation is possible for several varieties.