AIM: Being overweight or obese is a leading risk factor for several cancers,however,the association between excess weight and the risk of gallbladder cancer (GBC) remains controversial.The objective of this study was to determine the relative risk of GBC with regard to excess weight and female sex.METHODS: We performed a meta-analysis of 12 studies searched from PubMed and EMBASE databases,published up to December 2014.The outcome of interest was GBC incidence or morbidity; The exposure of interest was overweight and/or obesity defined by body mass index (BMI).Statistical analysis were performed by using Review Manager 5.0 (RevMan 5.0) software.P < 0.05 was considered significant.RESULTS: People with BMI ≥ 25 (i.e.,kg/m2) had higher risk of developing GBC than those with BMI < 25,with odds ratio (OR) 1.38 (95% CI:1.17-1.62; P < 0.01) in case-control studies,and the risk ratio (RR) 1.28 (95% CI:1.02-1.61; P < 0.03) in cohort studies respectively.Obese patients also had higher risk of developing GBC than non-obese patients,with RR 1.63 ( 95% CI:1.10-2.42; P = 0.02) in cohort studies and OR 1.43 (95% CI:0.99-2.05; P = 0.05) in case-control studies respectively.Women had higher risk of developing GBC than men,with OR 1.72 (95% CI:1.19-2.49; P = 0.004) for case-control studies and RR 1.30 (95% CI:1.22-1.39; P < 0.01) for cohort studies respectively.CONCLUSION: Our meta-analysis suggests that BMI ≥ 25 and female sex are risk factors for GBC.As excess weight is preventable,the risk of GBC can be decreased by maintaining a healthy body weight.