This study will a randomized clinical trial to compare the effectiveness of metformin and pioglitazone in treatment of women with polycystic ovary syndrome (PCO). Inclusion criteria: age between 18 to 40 years old; diagnosed PCOS by AES (Androgen excess soiciety2006) criteria include: 1. Oligo or anovulation 2. Clinical or biochemical hyperandrogenism and rejection any other reasen cause to hyperandrogenism. Exclusion criteria: pregnancy and lactation; impaired liver and renal function tests; thyroid disorder; hyperprolactinemia; adrenal disorders; patient on estrogen and progesterone pills; the presence of type 1 and type 2 diabetes mellitus; late-onset congenital adrenal hyperplasia, and Cushing’s syndrome; none of the women had been taking clomiphene citrate, oral contraceptives, antiandrogens, insulin, minoxidil, phenytoin, cyclosporine, or drugs to control their appetite, lipid profile, during the previous 3 months and any severe systemic disease. Seventy five women with PCOS aged 18-40 years old will be randomly allocated to one of the three treatment groups. Metformin group (25) will treat with metformin mono-therapy (1500mg daily) ; ; metformin plus pioglitazone group (25) will treat with metformin(1500mg daily) plus pioglitazone(30mg daily) and pioglitazone group(25) will treat with pioglitazone mono –therapy(30mg daily) for 3 months. Treatment will be discontinued once pregnancy will diagnose. All patients undergo clinical and biochemical evaluation and analyses involving the pre- and post-intervention fasting blood sugar (FBS), lipid profiles, body mass index (BMI), serum insulin, the homeostatic model assessment of insulin resistance (HOMA-IR), triglyceride, lower density cholesterol, high density cholesterol and DHEAS (dehydroepiandrosterone sulphate) LH/FSH,Total Testosterone،17-OHP, (17hydroxyprogestrone) waist to hip ratio in three groups.