ObjectiveThe Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) model and its Portsmouth (P-POSSUM) modification are used extensively to predict post-operative mortality and morbidity in general surgery. The aim was to analysis the predictive value of these models in patients undergoing hepatobiliary surgery. MethodsEligible articles were identified by searching such electronic databases as PubMed, The Cochrane Library (Issue 10, 2013), Science Citation Index, CNKI, WanFang Data and CBM from 1991 to October 2013. Each study was assessed according to the inclusion and exclusion criteria. Then data were extracted, pooled, and analyzed using Comprehensive Meta Analysis Version 2. ResultsTen studies were included. The morbidity analysis included five studies and 683 patients on POSSUM with a weighted O/E ratio 0.71 (95%CI 0.60 to 0.81). The mortality analysis included seven studies with 1 291 patients on POSSUM and six studies with 1 793 patients on P-POSSUM. Weighted O/E ratios for mortality were 0.42 (95%CI 0.27 to 0.57) for POSSUM and 0.74 (95%CI 0.53 to 0.95) for P-POSSUM. ConclusionPOSSUM significantly overestimates postoperative morbidity in patients undergoing hepatobiliary surgery. Compared with the original POSSUM, P-POSSUM is more accurate for predicting post-operative mortality. Modifications to POSSUM and P-POSSUM are needed for audit in hepatobiliary surgery.