Envenoming by the Australian red-bellied black snake (Pseudechis porphyriacus) causes non-specific systemic symptoms, anticoagulant coagulopathy, myotoxicity and local effects. Current management for systemic envenoming includes administration of one vial of tiger snake antivenom within 6 h of the bite to prevent myotoxicity. We present a case of severe rhabdomyolysis in a 16 year old male which developed despite early administration of one vial of tiger snake antivenom. Free venom was detected after the administration of antivenom concurrent with rapidly decreasing antivenom concentrations. The case suggests that insufficient antivenom was administered and the use of larger doses of antivenom need to be explored for red-bellied black snake envenoming.