INTRODUCTION It has been known for centuries that maggots are potent debriding agents capable of removing necrotic tissue and slough. In January 2004, the US Food and Drug Administration decided to regulate maggot debridement therapy (MDT). As it is still not clear which wounds are likely or unlikely to benefit from MDT, we performed a prospective study to gain more insight in patient and wound characteristics influencing outcome. PATIENTS AND METHODS In the period between August 2002 and December 2005, patients with infected wounds with signs of gangrenous or necrotic tissue who seemed suited for MDT were enrolled in the present study. In total, 101 patients with 117 ulcers were treated. Most wounds were worst-case scenarios, in which maggot therapy was a treatment of last resort. RESULTS In total, 72 patients (71%) were classified as ASA III or IV. In total, 78 of 116 wounds (67%) had a successful outcome. These wounds healed completely (n = 60), healed almost completely (n = 12) or were clean at least (n = 6) at last follow-up. These results seem to be in line with those in the literature. All wounds with a traumatic origin (n = 24) healed completely. All wounds with septic arthritis (n = 13), however, failed to heal and led in half of these cases to a major amputation. According to a multivariate analysis, chronic limb ischaemia (odds ratio [OR], 7.5), the depth of the wound (OR, 14.0), and older age (≥ 60 years; OR, 7.3) negatively influenced outcome. Outcome was not influenced by gender, obesity, diabetes mellitus, smoking, ASAclassification, location of the wound, wound size or wound duration. CONCLUSIONS Some patient characteristics (i.e. gender, obesity, smoking behaviour, presence of diabetes mellitus and ASA-classification at presentation) and some wound characteristics (i.e. location of the wound, wound duration and size) do not seem to contra-indicate eligibility for MDT. However, older patients and patients with chronic limb ischaemia or deep wounds are less likely to benefit from MDT. Septic arthritis does not seem to be a good indication for MDT.