The objective of this study was to assess the effect of oral treatment with Daflon 500 mg (micronized purified flavonoid fraction [MPFF]) on leg ulcer healing. This study was conducted as a meta-analysis of randomized prospective studies using Daflon 500 mg as an adjunct to conventional treatment. Medical literature databases and the manufacturer's records were searched for relevant clinical trials. Five prospective, randomized, controlled studies in which 723 patients with venous ulcers were treated between 1996 and 2001 were identified. Conventional treatment (compression and local care) in addition to Daflon 500 mg 2 tablets daily was compared with conventional treatment plus placebo in two studies (n = 309), or with conventional treatment alone in three studies (n = 414). The primary end point was complete ulcer healing at 6 months. The results are expressed as a reduction in the relative risk (RRR) of healing with 95% confidence intervals (CI). Since, in the present case, the desired treatment effect is increased ulcer healing, RRR should be positive to indicate a benefit of adjunctive Daflon 500 mg over conventional therapy alone. Type 1 error was set at 5%. At 6 months, the chance of ulcer healing was 32% better in patients treated with adjunctive Daflon 500 mg than in those managed by conventional therapy alone (RRR, 32%; 95% CI, 3% to 70%). This difference was present from month 2 (RRR, 44%; 95% CI, 7% to 94%), and was associated with a shorter time to healing (16 weeks vs 21 weeks; p = 0.0034). The benefit of Daflon 500 mg was found in the subgroup of ulcers between 5 and 10 cm2 in area (RRR, 40%; 95% CI, 6% to 87%), as well as in patients with ulcers of 6 to 12 months' duration (RRR, 44%; 95% CI, 6% to 97%). These results confirm that venous ulcer healing is accelerated by Daflon 500 mg treatment. Daflon 500 mg might be a useful adjunct to conventional therapy in large and longstanding ulcers that might be expected to heal slowly.