The secondary screwworm, Cochliomyia macellaria (Fabricius), usually deposits eggs on and develop in carcasses or human garbage. Due to this behavior, this blowfly is of medical and sanitary importance acting as mechanical vector of pathogens. This species is also of forensic importance because its larvae can feed on human carcasses. The distribution of C. macellaria ranges from southern Canada to northern Argentina. However, blowflies of the genus Chrysomya have invaded the Western Hemisphere in the 1970´s, displacing native species, especially C. macellaria. Therefore, it is important to use molecular markers for investigating many important aspects of the biology of C. macellaria, such as temporal and spatial population dynamics. Different molecular markers were previously used and suggested low levels of variability in natural C. macellaria populations. We are now focusing on a new class of molecular markers, the microsatellites. However, isolating new microsatellite loci is an expensive and time-consuming process. Therefore, it is interesting to use primer pairs designed for close-related species, which has achieved successful results in other studies. Here, we describe the applicability of microsatellite markers developed for C. hominivorax in C. macellaria population studies. Thirty C. hominivorax-derived primer pairs were used to amplify microsatellite loci in C. macellaria. Thirteen amplified products within the expected size range. These thirteen loci are now being tested for their polymorphism, in order to evaluate their applicability in population studies. Financial support: FAPESP.