The prevalence of metabolic disease type 2 diabetes is increasing. Numerous studies have to take into consideration in addition to the factors such as low mobility, nutrition and inheritance, environmental factors such as hexachlorobenzene in creation of type 2 diabetes. Therefore, it was tried in this study to obtain an exact result regarding the association of hexachlorobenzene with type 2 diabetes by doing a systematic review and metaanalysis of the cross-sectional and prospective studies which were received till 2 March 2016. After searching in the databases SID, Irandoc, Pubmed, Scopus, Ovid, Embase, ISI and Cochrane, 10 studies with 19 subgroups were considered in final assessment. Geometric mean concentration of Hexachlorobenzene was 12.7 ng/ml and 64.77 ng/g lipids in serum and adipose tissues, respectively. The heterogeneity index of I2:25.95% (I2<50%) and t2:0.075 were low and hence fixed model was used for meta-analysis of studies' results. The Pearson correlation coefficient between concentrations of hexachlorobenzene in serum and adipose tissue with the odds ratio of type 2 diabetes were R2:0.27, P value=0.57 and R2:0.25, P value=0.18, respectively. The highest and lowest odds ratios of type 2 diabetes was [OR:6.2 (0.6-68.1)] and [OR:0.99 (0.3-2.6)], respectively. Overall, the odds ratio for type 2 diabetes induced to hexachlorobenzene was OR:2.33 (1.82-2.74) P value<0.001. Results of this study supported the role of hexachlorobenzene significantly as an environmental risk factor in type 2 diabetes (P<0.001).