Objective Protobothrops mucrosquamatus, a Crotalinae snake with haemorrhagic venom, is responsible for the most common poisoning snakebites in Taiwan. Although a specific antivenin has been developed to treat this snakebite, surgical intervention is still needed in some patients because of the progression of tissue injury. Early risk stratification is important to identify the early signs of need for surgery. The purpose of this study was to investigate the early predictors for surgery in patients with P. mucrosquamatus envenomation. Methods The medical records of inpatients with P. mucrosquamatus envenomation between 2008 and 2013 were retrospectively reviewed. Clinical information was collected and analysed between surgical and nonsurgical patients. Results A total of 60 patients with P. mucrosquamatus envenomation, including 8 surgical patients (13.3%) and 52 non-surgical patients (86.7%), presented to the emergency department during the study period. Compartment syndrome (62.5%) and tissue necrosis (37.5%) were the main reasons for surgery. Comparison between surgical and non-surgical patients showed significantly higher white blood cell count (17.1 × 103/μL vs. 8.5 × 103/μL; p=0.002) and peak D-dimer level (1924.8 ng/mL vs. 730.0 ng/mL; p=0.006) in the surgical group. Ecchymosis (p=0.009), haemorrhagic bulla formation (p=0.002), leukocytosis (p=0.002), elevated peak D-dimer level (>1000 ng/mL) (p=0.005), and rhabdomyolysis (creatine kinase level >1000 IU/L) (p=0.007) were the significant signs relevant to surgery. On multivariate analysis, leukocytosis and ecchymosis were the most significant predictors of surgery in patients with P. mucrosquamatus envenomation. Conclusions Patients with P. mucrosquamatus envenomation presenting with leukocytosis and wound ecchymosis will have a high probability of requiring surgical therapy. (Hong Kong j.emerg.med. 2016;23:210-219)