Abstract: Background: PPARγ agonists are used in type 2 diabetic patients to reduce insulin resistance. Recently, many AT1 receptor antagonists (ARBs) were reported to function as a partial agonist of PPARγ based on in vitro experiments. The aim of the present study was to investigate the effects adjuvant use of ARBs (losartan, telmisartan or valsartan) with metformin on metabolic and hormonal status in women with polycystic ovary syndrome (PCOS). Methods: Using single-blinded clinical trial, we compared the effects of losartan, telmisartan or valsartan, when adjunctly used with metformin, on insulin sensitivity, body mass index, glycemic control the serum levels of various hormones (FSH, LH and testosterone). In total, 74 Iraqi females with PCOS were enrolled in the study and allocated into 4 treatment groups; metformin only (1000 mg day-1) and metformin with losartan (25 mg), telmisartan (40 mg) or valsartan (40 mg) groups. Results: All ARBs significantly reduced BMI, FBG and C-peptide values compared to metformin only treated group; they also showed significantly greater effects in increasing plasma levels of FSH and decreasing both LH and testosterone levels compared to metformin only. The rank for the effects of the used ARBs in this respect was: telmisartan>losartan>valsartan after 4 months of treatment. Conclusion: Adjuvant use of ARBs with metformin improves its effect in treatment of women with PCOS, with most pronounced effect for telmisartan in this respect.