Secretions of larvae of the blowfly Calliphora erythrocephala digested experimental rat skin burn eschar in vivo and in vitro when applied topically in a vanishing cream base. Debridement was characterized by de-epithelialization and digestion of dermal collagen to a subfollicular level over a 3-day period. Analytic investigation of the secretions demonstrated the presence of enzymes with activities characteristic of trypsin, leucine aminopeptidase, and carboxypeptidases A and B. These were partially characterized. There was no evidence of chymotrypsin, elastase, or collagenase. Preparation of a suitable therapeutic form could result in a preparation useful for enzymatic debridement.