A case of mixed semi-specific cutaneous myiasis produced by larvae from Calliphora vicina Rob.-Desv. and Lucilia sericata Mg, in their third development stage, is described, as the first case in humans, although there is a precedent described in domestic animals. Main taxonomic characteristics and diagnostic features of the parasites are discussed, together with the implications of their biology in the observed clinical case, discussing, as well the prophylaxis and therapy.