Objectives: To study effect of erythropoietin (EPO) on some aspects of carbohydrate and lipid metabolism in obese and diabetic rats. Material and methods. This study was carried on (50) albino female rats; divided into 5 groups, each consisted of 10 rats: Control, obese, diabetic, erythropoietin treated obese group (after induction of obesity it was injected by erythropoietin 600u/kg I.P. once daily every other day for 5 weeks) and erythropoietin treated diabetic group (after induction of diabetes it was treated as previous group). At the end of experimental period serum samples were collected for estimation of: fasting serum glucose, serum insulin, insulin resistance (HOMA IR), insulin sensitivity (HOMA S%), serum LDL, serum HDL, serum triglyceride (TG), serum cholesterol, glycosylated Hb% and measurement of body mass Index (BMI) Results: Erythropoietin treated obese group showed significant decrease in fasting glucose, insulin, HOMA IR, serum LDL, TG, cholesterol and BMI. While, serum HDL and HOMA S% were significantly increased when these results were compared to obese group. Erythropoietin treated diabetic group produced insignificant change in all studied parameters with exception of significant decrease in fasting glucose, TG and glycosylated Hb% when these results compared to diabetic group. Conclusion: EPO can be considered as adjunct anti-diabetic/obesity drug to reduce blood glucose, hypolipidemic effect and attenuate weight gain.