Calf muscle pump function was assessed in 41 limbs after venous ulcers had healed. Treatment was then randomized either to ligation of incompetent lower leg communicating veins and ablation of incompetent superficial veins combined with permanent graduated compression elastic stockings, or to graduated compression elastic stockings only. Half volume refilling time (TV1/2) and relative expelled volume (EVrel) measured on foot volume plethysmography were used to assess calf muscle pump function. This was repeated after 12 months. The initial TV1/2 and EVrel were significantly lower than for normal limbs. There was no significant improvement in TV1/2 in either treatment group (Student's t test, P = 0.78, P = 0.19). EVrel did not improve significantly in limbs treated with elastic stockings alone (P = 0.94), but there was a slight but significant improvement in EVrel in limbs treated with surgery and elastic stockings (P = 0.048); however, this was still significantly below the normal range (P<0.001). In limbs without phlebographic evidence of post-thrombotic changes, treated with the combination of surgery and elastic stockings, there was a significant improvement in EVrel (P = 0.035), but no improvement was found in limbs with post-thrombotic changes. This small but significant improvement in EVrel in limbs without post-thrombotic changes treated by surgery and elastic stockings may explain the reduced incidence of reulceration that has been found following surgical eradication of the superficial and communicating veins.