Using the immunofluorescence technique we have studied the distribution of fibronectin in cultured fibroblasts from patients affected by Ehlers-Danlos Syndrome (EDS) types I, II and VI. In these cells the amount of fibronectin production is reduced with respect to normal fibroblasts; moreover fibronectin fibers are shorter, thicker, mainly pericellular and show intracytoplasmic accumulation. The altered fibronectin distribution may be the result of altered interactions of fibronectin with extracellular matrix components, either due to abnormal fibronectin or to changes in other extracellular matrix molecules (e.g. collagens, hyaluronic acid).