Local and systemic hemorrhages are major problems concerning bites by viper snakes. Therefore, accessing venom hemorrhagic activity is an important feature in order to characterize viper venom major toxicities or to assay antivenom efficacy. The methods currently used to access hemorrhagic activity involve animal experiments and according to the general ethical committees, these procedures should be substituted to in vitro assays in order to minimize animal use in research. In this work, we have developed an immunoassay to detect the content of hemorrhagic metalloproteinases in snake venoms using a neutralizing monoclonal antibody anti-jararhagin (MAJar 3). The correlation between the reactivity of this monoclonal antibody and venom-induced hemorrhage was further revealed by a study comparing the hemorrhagic activity of venom samples collected individually from 88 specimens of Bothrops jararacussu with their reactivity with MAJar 3. As a result, a significant correlation (r=0.942) was achieved between samples hemorrhagic activity and their reactivity with MAJar 3, suggesting that this assay can be used as a substitute of the conventional tests performed in vivo to estimate the hemorrhagic activity.