The expansion of the obesity epidemic is accompanied with an increase in bariatric procedures, in particular in women of reproductive age. Severe obesity has negative effects on fertility and on in vitro fertilization (IVF) outcomes, and the weight loss induced by the bariatric surgery (BS) is believed to reverse the deleterious impact of overweight and obesity on female fertility. However, research is limited to retrospective cohort studies, small case-series and case-control studies. Weight reduction has been shown to improve fecundity and hormonal state of a subgroup of obese patients with polycystic ovary syndrome (PCOS). In this population, recent studies have demonstrated an increase of naturally conceived pregnancies following bariatric surgery. However, these studies have evaluated only short-term evolution of ovarian function and not all studies demonstrated improvements in fertility outcomes after BS. Clearly, more studies are needed regarding the effect of BS on obesity-related infertility, and long-term outcome of ovarian function has to be assessed. Markers of ovarian reserve, including Follicle Stimulating Hormone (FSH), antral follicle count (AFC), and anti-mullerian hormone (AMH), have been used to counsel patients regarding in their reproductive outcomes. Serum AMH concentrations remain remarkably stable throughout the menstrual cycle, which is a great advantage over other markers of fertility. Various studies have evaluated the association between AMH and body mass index (BMI) but reported contradictory results. Some of them have reported a significant inverse correlation between AMH and BMI, but others found no relationship between AMH and BMI. Scarce and small preliminary studies have been performed to evaluate AMH changes after surgical weight loss and showed a decrease in serum AMH.