In a case of spherocytosis combined with ulcus cruris, Doppler sonography and phlebography revealed a chronic venous insufficiency, together with fibrinous precipitates in capillary and venous vessel walls. Some haemolysis and fragmentation of red cells in the biopsy was also observed. It is suggested that the haemodynamic alteration due to chronic venous insufficiency may have played the main role in the development of the ulcers, although the rheological disturbance caused by the spherocytosis may have had an aggravating effect. Circulatory disorders should be excluded, if skin ulcers are to be classified as haematological disorders.