The abnormal cauliflower collagen fibrils present in skin of patients with Ehlers-Danlos type I were studied by electron microscopy and computerized image analysis. The size control of the few fibrils displaying a cauliflower shape is apparently lost, eventuating in an increased amount of collagen polymers constitutive of these fibrils. This situation is fundamentally different from that occurring in dermatosparaxis, an animal disease considered as a model for Ehlers-Danlos syndrome.