We identified 22 studies assessing the association between pesticides and diabetes. The summary OR for the association of top vs. bottom tertile of exposure to any type of pesticide and diabetes was 1.58 (95% CI: 1.32–1.90, p = 1.21 × 10− 6), with large heterogeneity (I2 = 66.8%). Studies evaluating Type 2 diabetes in particular (n = 13 studies), showed a similar summary effect comparing top vs. bottom tertiles of exposure: 1.61 (95% CI 1.37–1.88, p = 3.51 × 10− 9) with no heterogeneity (I2 = 0%). Analysis by type of pesticide yielded an increased risk of diabetes for DDE, heptachlor, HCB, DDT, and trans-nonachlor or chlordane.