Background: brain-derived neurotrophic factor (BDNF) is a27-kDa polypeptide that belongs to the neurotrophin family binding with high-affinity protein kinase receptors (Trk) and the unselective p75NGFR receptor. The BDNF gene has a complex structure with multiple regulatory elements and four promoters that are differentially expressed in the central or peripheral tissue. Aim of the Work: this study aimed to detect affection of follicular fluid neurotrophin level in different types of infirtility and its using as peredictor for ovarian reserve. Patients and Methods: this crosssectional study was carried out in Ain Shams University, Maternity Hospitals Assisted Reproductive Technology Unit (ART unit) in the period from Septemper2016 to June 2017. Results: the present study showed a cut-off value of BDNF for the patients who underwent this study was 2.7 pg/ml with sensitivity of 74.2%, specificity 95.5%, PPV 85.2% and NPV 91.4%. Conclusion: FF-BDNF measurement on the d-OPU in women with different types of infertility underwent COH for IVF-ET, had positive correlation with ovarian reserve and positive predictor of pregnancy which occurred in 25.8% of cases. Recommendations: BDNF has positive correlation with ovarian reserve and positive correlation with pregnancy outcome so we recommend to measure serum BDNF before starting IVF cycle as predictive factore and cost effective.