Seven patients with scleroderma were each treated with an infusion of one liter of a 10% solution of dextran 40 in physiological saline during an 18-hour period. Measurements of total blood flow and capillary filtration coefficient (CFC) by electro-capacitance plethysmography as well as by sodium iodide I 131 clearance were recorded before and after treatment with low molecular weight dextran. All posttreatment blood flow and CFC values for these patients were significantly increased, and all of the patients experienced subjective improvement of their lesions.