The main objective of the trial was to study the efficacy of bagged larvae on wound debridement in comparison to classical treatments. The secondary outcome was to assess wound healing, treatment related pain, microbiological modifications, adverse events, comfort of the dressing and duration of wound care. We performed a randomized, double-blind, multicenter, controlled, prospective phase III trial in three referral institutional centers of hospitalized care in Caen, Lisieux and Lyon, France. A total of 120 patients with a non-healing fibrinous wound ≤ 40cm2, less than 2cm-deep, and an ankle-brachial pressure index (ABPI) ≥ 0.8 were included, from March 2005 to December 2008. During two weeks´ hospitalization, patients received either Maggot Debridement Therapy (MDT, changes of bagged larvae twice a week) or classical treatments (mechanical debridement and classical dressings performed three times a week). At discharge, classical dressings were applied and a follow-up visit performed at D30. Main outcome measure was the comparison of the reduction of fibrin percentage on wounds treated with MDT and classical treatments at D15. The percentages of fibrin were measured using a computerized planimetry software package, Canvas (ACD Systems, British Columbia, Canada), which enables the quantification of color surface variations in a wound after manual delimitation (using a mouse) on a series of photographic images.