Purpose of Investigation: The aim of this study is to determine the differentiation between follicular fluid (FF) anti-Müllerian hormone (AMH), inhibin-A, progesterone (P), and estradiol (E2) levels in patients with poor response, normal response, and high response after controlled ovarian stimulation and the relationship between this differentiation and pregnancy outcome. Materials and Methods: The prospective study included 64 patients who applied for IVF treatment, during a two-month period, in Gazi University Infertility Center. Patients were evaluated in three groups: poor-responders (n=18), normo-responders ( n=26), and high-responders ( n=20), for their controlled ovarian stimulation response. Quantitative measurements of AMH, inhibin-A, P, and E2 were made by ELISA. Results: The FF, AMH, inhibin-A, E2, and P levels were all found to be similar in the groups. The pregnancy rates were 11.0% in the poor-responders, 27.0% in the normo-responders, and 16.7% in the high-responder group. Although higher inhibin-A, AMH, P, and E2 hormones were all detected in the non-pregnant, as compared to the pregnant patients, no statistically significant relationship was found. Conclusion: In this study, inhibin-A, P, E2, and AMH hormone FF levels were not found to be correlated with the ovulation induction response nor effective for predicting the pregnancy outcome.