Polycystic ovary syndrome (PCOS), is a complex condition that affects women of reproductive age, women with PCOS present a prevalence of obesity. Current study aims to evaluate the adiponectin level and its gene polymorphism (+276 T /G). The patients and control women samples were collected from May 2022 to March 2023. 140 samples were collected ages from 18 to 40 years old from the Maternity Teaching Hospital, they divided into two groups: Group I: 70 obese control and Group II: 70 obese PCOS. Using PCR for allele-specific amplification refractory mutation system (ARMS). Serum specimens were collected for the measurement of many biochemical parameters. Results showed that adiponectin levels in PCOS decreased significantly, while leptin increased significantly when compared to control. HOMA-IR, Glucose, Insulin, and Testosterone parameters increased significantly in PCOS, while SHBG increased non-significantly. MDA and vit. D parameters increased significantly in PCOS, while vit.C showed a significant decrease. Serum cholesterol level was increased non-significantly in patients with PCOS group as compared to the control group, HDL was decreased significantly in PCOS women, while non-significant increase was observed in LDL, TG, and VLDL as compared to control women. The participants with homozygous for the G allele of the adiponectin (+276 T/G) had a significant and increased risk of PCOS with a significant decrease in adiponectin  in PCOS. This study concluded that the decreased serum adiponectin can serve as a valuable biomarker for diagnostic PCOS in obese women, and G allele of the adiponectin showed an increased risk for PCOS.