In this study, the effect of diosmin against the adverse effects of lead exposure in rats was investigated. Wistar Albino race 40 male rats weighing 150-200 g 2-3 months were used. A total of 4 groups were assigned, one of which was control and the other 3 were trial groups. The rats in the control group were treated with dimethyl sulfoxide, which was used only as a vehicle in diosmin administration. Groups 2, 3, and 4 from the experimental group were given diosmin at a dose of 50 mg/kg.bw, lead acetate at the dose of 1000 ppm, lead acetate at the dose of 1000 ppm, and diosmin at a dose of 50 mg/kg.bw for 6 weeks, respectively. Application of lead acetate with drinking water and also diosmin was performed by oral catheter. At the end of the experimental period, blood was taken to dry and with heparin by puncture to the heart under light ether anesthesia. Following the blood samples, some organs of the rats (the liver, kidney, brain, heart, and testis) were removed. Some biochemical parameters (glucose, triglyceride, cholesterol, BUN, creatinine, uric acid, LDH, AST, ALT, ALP, total protein, albumin) were measured in serum. Some oxidative stress parameters in tissue samples and blood (MDA, NO, SOD, CAT, GSH-Px, GSH) were evaluated. Body and organ (the liver, kidney, brain, heart, and testis) weights were also evaluated at the end of the study. No significant change was observed in the parameters examined in the diosmin alone-treated group by comparison to control group. On the other hand, significant changes were found in the values of lead acetate-treated group comparing control group. It was observed that the values approached the values of the control group in the combination of lead and diosmin. Exposure to lead acetate at a dose of 1000 ppm for 6 weeks causes organ damage; however the diosmin application at a dose of 50 mg/kg.bw had a positive effect on the regression of tissue damage.