A new mixture of the screwworm,Cochliomyia hominivorax(Coquerel), chemical attractant was prepared and evaluated under field conditions. This new mixture, “Swormlure-2,” proved to be more attractive to screwworms than the mixture presently being used and at least as attractive as decomposing liver. In general, more unmated female flies were attracted to Swormlure-2 than were attracted to liver. Also, Swormlure-2 appeared to be more attractive than liver to unmated females that were in early stages of egg development.