Obesity has major adverse effects on reproductive performance and fertility potential especially in women with polycystic ovary syndrome. In this study, we aimed to evaluate the consequences of excess weight reduction by bariatric surgery on androgen levels, and ovarian volume by ultrasonography in obese polycystic ovary patients. This one year Cohort study was carried out in Zagazig university hospitals. The study included 36 infertile women with PCOS and obesity, who underwent bariatric surgery (sleeve gastrectomy or gastric bypass). Patients were evaluated for free and total serum testosterone levels, Sex hormone binding globulin (SHBG), free androgen index (FAI) and also ovarian volume by ultrasound pre-operatively, 6 months and 1 year after surgery. The results showed significant reduction in Body Mass Index, free and total serum testosterone levels and rise in SHBG and regulation of menstrual cycle at 6 and 12 months after operation. Free androgen index and ovarian volume by ultrasound also significantly decreased (p < 0.001) .As a conclusion, Bariatric surgery results in durable loss of weight and restores the normal physiological balance of androgenic milieu and ovarian morphology by ultrasound, in infertile women who have Polycystic ovary syndrome.