AbstractSixteen patients with arteriosclerosis and pre‐gangrene of a lower limb were treated for 5 days by intravenous injection of Arvin. The effects of the injection on plasma fibrinogen, the viscosity of blood and the patient's symptoms were measured. There was a 90 per cent reduction in plasma fibrinogen and a significant reduction in the viscosity of blood. Five patients experienced some relief of pain during the treatment. In only one patient were the symptoms relieved permanentl