Conception, design, intellectual and scientific content of the study; critical analysis; final approval. ABSTRACT PURPOSE:To investigate the effects of hydroalcoholic leaf extract of Mikania glomerata Spreng (Asteraceae) on the activity of Bothrops jararaca snake venom in Wistar rats. METHODS:Fifty four rats Wistar were divided into six groups of nine animals in each: control treated with saline; control treated with B. jararaca venom; control treated with M. glomerata extract; B. jararaca venom incubated with M. glomerata extract at proportions of 1:1, 1:2, and 1:4. RESULTS: Histopathological and morphometric analysis showed that intradermal administration of snake venom incubated with the hydroalcoholic extract at proportions of 1:1, 1:2 and 1:4 promoted a significant reduction in the number of inflammatory cells and a marked decrease in edema after the third hour. There was also a significant reduction in the intensity of the hemorrhagic halo in animals receiving the snake venom incubated with the extract, with the observation of a progressive and parallel inhibition with increasing proportion of M. glomerata. CONCLUSION:The Mikania glomerata hydroalcoholic extract exerted effective anti-inflammatory and antihemorrhagic activity against the effects induced by Bothrops jararaca snake venom.