ObjectiveTo systematically review the efficacy of lamivudine (LAM) plus adefovir (ADV) versus entecavir (ETV) monotherapy for LAM-resistant chronic hepatitis B patients. MethodsWe electronically searched databases including PubMed, The Cochrane Library (Issue 12, 2013), CBM, CNKI, VIP, WanFang Data from their inception to December 2013, to collect randomized controlled trials (RCTs) or cohort studies of LAM+ADV versus ETV for LAM-resistant chronic hepatitis B. Two reviewers independently screened literature according to the inclusion and exclusion criteria, extracted data and assessed the methodological quality of included studies. Then, meta-analysis was performed using RevMan 5.2 software. ResultsA total of 13 RCTs and 5 cohort studies involving 1 336 patients were included. The results of meta-analyses of RCTs showed that:there were no significant differences between the LAM+ADV group and the ETV group in the negative rates of serum HBV-DNA (RR=1.00, 95%CI 0.91 to 1.10, P=0.94), HBeAg (RR=0.90, 95%CI 0.70 to 1.17, P=0.43), serum ALT recovery rate (RR=0.97, 95%CI 0.90 to 1.05, P=0.45) and serum HBeAg conversion rate (RR=0.71, 95%CI 0.40 to 1.24, P=0.22) at the 48th week. The results of meta-analyses of cohort studies showed that:there were no significant differences between the two groups in the negative rates of serum HBV-DNA (RR=1.37, 95% CI 0.91 to 2.06, P=0.13) and serum ALT recovery rate (RR=0.99, 95%CI 0.87 to 1.12, P=0.87), but the ETV group had higher serum HBeAg conversion rate (RR=0.24, 95% CI 0.07 to 0.79, P=0.02). ConclusionCurrent evidence shows that the efficacy of LAM+ADV is similar to ETV at the 48th week for LAM-resistant chronic hepatitis B patients. Due to limited quality and quantity of the included studies, more high quality studies are needed to verify the above conclusion.