In slow-healing wounds, i.e. those with little granulation tissue with deep necrotic tissue and exudation, complicated by inflammation, there is depolymerization and degradation of local mucopolysaccharides, especially hyaluronic acid. A local deficit of hyaluronic acid leads to insufficient regeneration of connective tissue, poor angiogenesis and deficient differentiation of histiocyte and fibroblast populations. Exogenous hyaluronic acid applied to a debrided wound keeps it moist and ensures a high concentration at the site of action. Hyaluronic acid stabilizes the clot matrix, attracts inflammatory, mesenchymal and epithelial cells into the wound area and enhances angiogenesis of the clot tissue. It also exerts an antiexudative, vasoprotective and fibrogenic action in inflamed tissues of slow-healing wounds. In this multicentre controlled study we evaluated the efficacy and safety of hyaluronic acid in 50 patients with venous leg ulcers in comparison with Dextranomer, the product of choice for this indication in France. Objective parameters, including the appearance and dimensions of the ulcer, improved significantly in both treatment groups. However, there was a faster and greater reduction in the ulcer dimensions following treatment with hyaluronic acid. Both treatments improved surrounding erythema, pain, oozing and necrosis but only hyaluronic acid caused a significant decrease in oedema. A greater number of positive efficacy judgements were seen in the hyaluronic acid group. The local tolerability of the two treatments was excellent. Hyaluronic acid is therefore a safe and effective treatment for patients with venous leg ulcers.