Three monoclonal antibodies (WPN1, WPN2 and WPN3) raised against a partially purified fraction of Russell's viper venom (RVV) were characterized. All three monoclonal antibodies reacted with crude RVV when tested by ELISA, but only two (WPN1, WPN2) neutralized its hyaluronidase activity. WPN1 was the more potent and was effective at an antigen: antibody ratio of 1:3. Furthermore, WPN1 was shown to recognize only the 14,000 MW component of crude RVV. This has been identified in a previous study to be hyaluronidase. This antibody was also found to recognize some components of Calloselasma rhodostoma venom which also possesses potent hyaluronidase activity. The potential therapeutic role of antibodies that neutralize the hyaluronidase component of snake venoms should be investigated further.