ABSTRACT Background: Poly cystic ovary syndrome (PCOS) is the principal cause of anovulatory infertility.Adropin is a nutrient-regulated metabolic hormone shown to encourage glucose oxidation over fatty acid oxidation.Vaspin expression in visceral adipose tissue is associated with metabolic derangement in rat model of obesity and T2DM.Some studies addressed adropin and vaspin levels in PCOS, however, the results are controversial. Aim of the study: This study was designed to evaluate both serum adropin and vaspin levels in obese rats with PCOS and to detect any possible association of these levels with metabolic and hormonal changes in this condition with and without metformin treatment. Material and Methods: Twenty four female albino rats were divided into three equal groups. Group I:Control,Group II:obese rats with PCOS fed HFD for 9 weeks and given letrozole(1mg/kg BW)by gavage daily for the last 21 consecutive days. Group III:Metformin pretreated obese PCOS rats, at a dose of 200 mg/kgBW daily along with letrozole for the last 21days.At the end of the experiment, Serum adropin, vaspin, sex hormones, insulin, glucose, lipid profile, TNF, plasma D-dimer and ovarian MDA levels were estimated. BMI, HOMA-IR were calculated. Ovarian histopathology was done. Results: Obese PCOS group showed significantly lower serum adropin and higher vaspin levels when compared to control group. Metformin pretreated group showed significantly higher serum adropin and lower vaspin levels when compared to obese PCOS group.Adropin was negatively correlated with all parameters except sex hormones.Vaspin was positively correlated with all parameters except sex hormones in all groups. Conclusion: Adropin and vaspin may represent a novel link between obesity and metabolic disturbance in obese PCOS rats. Keyword:Adropin,vaspin,obesity,PCOS,metformin. Corresponding author: