Diabetes is associated with several structural and functional liver abnormalities that affect glycogen and lipid metabolism. In this study, an attempt was made to evaluate the effects of hydroalcoholic extract of Urtica dioica leaves on Quantitative morphometric changes in parenchymal cells of the livers in STZ diabetic rats. Thirty male Wistar rats were allocated in 3 groups: normal, diabetic and treatment. Hyperglycemia was induced by 80 mg/kg Streptozotocin intraperitoneally. One week after the injection of STZ, the third group received the hydroalcoholic extract of Urtica dioica at 100 mg/kg/day over four weeks. After five weeks, the animals were sacrificed and whole livers were removed. Liver specimens were used for quantitative morphometric analyze after hematoxylin and eosin staining. All data are shown as means plus standard errors of means and were analyzed using One-Way ANOVA test at P<0.05.The mean area of hepatocytes, nuclei and nucleolus had a decrease in periportal zone and an increase in perivenous zone in the diabetic and treatment groups. The increase of hepatocyte area in perivenous zone and reduce of nucleus area in periportal zone was significant in the diabetic group in comparison with control group (P<0.05), but were not significant between treatment and diabetic group. This study showed that administration of 100 mg/kg/day of Urtica dioica leaves extracts after induction of diabetes can cause a little modulating in the main morphometric indices of liver such as area of hepatocytes, nuclei and nucleolus in periportal and perivenous zones
