Introduction: Adiponectin is a protein hormone secreted from adipose tissue that can affect diabetes progression. The aim of this study was to investigate the changes in serum levels of adiponectin in diabetic rats treated with alcoholic and aqueous extracts of three medicinal plants, jujube (Ziziphus jujuba), barberry (Berberis vulgaris) and saffron (Crocus sativus). Materials and Methods: In this study, streptozocin-induced diabetic rats were treated with two doses of aqueous and alcoholic extracts of the herbs, 25 and 100 mg/kg respectively, for 21 days. After the treatment period, the levels of adiponectin, fasting blood glucose, triglycerides and cholesterol were measured and the results were analyzed using one way ANOVA test. Results: In all the diabetic groups receiving extracts, serum levels of fasting blood glucose, triglycerides and VLDL (very low density lipoprotein), showed a significant decrease (P<0.05). Serum level of HDL (high density lipoprotein) increased significantly only in the group receiving jujube (P<0.05), whereas adiponectin level was significantly increased in all the treated groups. Conclusion: Given the role of adiponectin in regulating lipid metabolism, and the increased level of adiponectin in the treated diabetic groups, it can be said that the extracts regulate glucose and lipid metabolism by changes in adiponectin level. Further studies are recommended to confirm these findings.