A double-blind, placebo-controlled study was carried out in 12 patients suffering from chronic venous insufficiency and persistent leg ulcers to assess the efficacy of pentoxifylline treatment as an adjunct to compression bandaging in the conservative management of venous leg ulcers. Six patients were allocated at random to receive twice-daily infusions of 200 mg pentoxifylline intravenously and 400 mg pentoxifylline orally 3-times daily for 7 days then 400 mg oral doses 3-times daily for a further 60 days. The control group received matching placebo in an identical regimen. Treatment outcome was assessed by changes between the start and end of the study in venous ulcer surface area, and continuous wave Doppler ultrasound was used to monitor ankle/arm systolic pressure ratio, venous pressure at the ankle, valvular competence and possible venous reflux at intervals throughout the study period. The results showed that in the patients treated with pentoxifylline complete ulcer healing took place in 4 out of 6 and there was a significant reduction in mean ulcer surface area. In the control group, complete ulcer healing was recorded in 1 out of 6 patient only and the ulcer area was only moderately reduced in the others. There was no statistically significant differences between the two groups in the variables monitored by Doppler ultrasound but the difference between treatment outcome was significant. Treatment was well-tolerated.