Introduction: An exaggerated FSH/LH ratio, even with normal FSH, is a sign of diminished ovarian reserve. In fact, the ratio of FSH/LH appears to be a clinically useful index, suggesting diminished ovarian reserve with FSH exceeds LH. Objective: To evaluate the day 3 FSH/LH ratio as a predictor of prognosis in IVF cycles. Design: A retrospective cohort study.Materials and Methods: Six hundred eighty-four women younger than 40 years old with day 3 FSH levels of 10 IU/L undergoing their first IVF cycle was stimulated with a variable protocol and evaluate the relationship between FSH/LH ratio and Total dose of hMG, IU and mature oocyte yield and pregnancy rate.Results: In group that FSH/LH ratio<2 improved (p<0.0001) ovulatory response in comparison to Groups FSH/LH ratio>2. The long of cycle & dose of gonadotropin was lower (p<0.0001) in FSH/LH ratio<2 than Group FSH/LH ratio>2.Conclusion: An increased FSH/LH ratio was associated with higher dose of HMG and increase day of stimulation and decrease of mature oocyte.