Background: Endometriosis is a common disease that affects 10% of reproductive-age women, which extrapolates to approximately 190 million women worldwide. 
Objectives: we aimed to assess the prognostic value of serum anti-endometrial antibodies estimation in connection to the implantation rate in endometriosis patients with recurrent implantation failure who underwent intracytoplasmic sperm injection cycles (ICSI).
Patients and Methods: A prospective cohort study examined infertile patients with endometriosis who underwent ICSI cycles after recurrent implantation failure at assisted reproduction units, Obstetrics and Gynecology departments, South Valley University, and Cairo University. All patients were evaluated and serum anti-endometrial antibodies were measured, followed by an ICSI procedure, and the implantation rate was recorded
Results: 32 patients were included; 24 (75%) had primary infertility, and 8 (25%) had secondary infertility. Antiendometrial antibodies were positive in 21 (65.62%) patients, with a significant negative correlation between anti-endometrial antibodies and implantation rate in patients with recurrent implantation failure (P= 0.010).
Conclusion: Serum anti-endometrial antibodies exhibited a negative association with implantation rate and oocyte quality, suggesting a potential use as a biomarker in endometriosis patients with recurrent implantation failure undergoing ICSI cycles.