BACKGROUND Both four-layer and three-layer paste bandages are widely used in the treatment of venous leg ulcers. The aim of this study was to compare the efficacy of these two bandaging regimens. METHODS The study was a prospective, randomized, open comparison of a consecutive cohort of 133 patients with venous ulcers. Participants were stratified by ulcer size into one of three groups and were randomized within each group to receive either three-layer paste or four-layer bandages. All patients were followed for 1 year. The time taken to complete ulcer healing was the primary endpoint. The time taken to apply the bandages, comfort, tolerability and cost were also assessed. Analysis was performed on the basis of intention to treat. RESULTS Ulcers healed completely in 51 (80 per cent) of 64 patients treated with three-layer paste bandages compared with 45 (65 per cent) of 69 patients treated with the four-layer regimen (P = 0.031). This difference developed only after 20 weeks of treatment. The median times to complete healing were 12 weeks for three-layer and 16 weeks for four-layer treatment (P = 0.040). Results of venous function tests, including half-refilling times, were similar in the two groups. CONCLUSION Three-layer paste bandages were significantly more effective at healing venous ulcers than the four-layer regimen in this study.