ObjectivesTo systematically review the association between serum leptin level and hepatitis C virus.MethodPubMed, EMbase, Web of Science, CNKI, CBM, VIP and WanFang Data databases were electronically searched to collect case-control studies on the association between serum leptin level and hepatitis C virus from 2007 to July, 2017. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then, meta-analysis was performed by using RevMan 5.3 software.ResultsA total of 11 studies including 1 115 patients were included. The results of meta-analysis showed the serum leptin level was higher in hepatitis C patients than in healthy people (SMD=0.68, 95%CI 0.44 to 0.91, P<0.000 01). The results of subgroup analysis showed that, in hepatitis C patients whose serum leptin levels detected by RIA and European population, serum leptin levels were higher. Women had higher serum leptin levels than men in hepatitis C virus patients (P<0.000 01).ConclusionThe serum leptin level is associated with hepatitis C virus and the serum leptin levels of women are higher than those in men. Due to limited quantity and quality of the included studies, more high quality studies are required to verify above conclusions.