Botropase is a snake venom-based hemocoagulase with thrombin-like activity 1. Despite its clinical use over several decades, its therapeutic effect has been controversial, and no study about botropase effect on platelet function has been reported. In this report, we present two cases with markedly decreased platelet function after receiving intravenous botropase, especially one of whom, with end stage renal disease (ESRD), showed a severe bleeding complication. On April 20, 2020, a 59-year-old man (case 1) visited our hospital for spinal stenosis surgery. His past medical history was pertinent, with diabetes diagnosed at the age of 40 and hemodialysis since February 2017. He did not take any antiplatelet medications for several months before the surgery. Initial laboratory findings showed white blood cell count 8.8 × 103 /µL, hemoglobin 10.0 g/dL, hematocrit 29%, platelet count 162 × 103 /µL, blood urea nitrogen 45 mg/dL, creatinine 6.3 mg/dL, glucose 92 mg/dL, prothrombin time 13.4 seconds, protein C activity 97%, protein S activity 78%, von Willebrand factor 150%, antithrombin III 80%, and fibrinogen 116 mg/dL. KCI Citation Count: 0