Sandwich-type enzyme linked immunosorbent assays (ELISA) were developed to detect Lachesis muta muta (bushmaster) snake venom using antibodies against the plasminogen activator enzyme (LV-PA). Antibodies to LV-PA were obtained by immunization of one rabbit with the purified enzyme. The IgG fraction was purified from rabbit blood in a single step on a column of Sepharose-L. m. muta venom and used to coat the microtiter plates. The specificity of the assay was demonstrated by its capacity to correctly discriminate between the circulating antigens in mice that were experimentally inoculated with L. m. muta venom from those in mice inoculated with venoms from Bothrops atrox, B. brazili, B. castelnaudi, Bothriopsis taeniata, B. bilineata, Crotalus durissus ruruima and the antigenic Bothrops (AgB) and Crotalus (AgC) pools venoms used to produce Bothropic and Crotalic antivenoms at Fundacao Ezequiel Dias (FUNED). Measurable absorbance signals were obtained with 1.5 ng of venom per assay. The ELISA was used to follow the kinetic distribution of antigens in experimentally envenomed mice.