Background: Hysteroscopy is one of the most important investigations in women with recurrent implantation failure (RIF). It allows reliable visual assessment of the cervical canal and uterine cavity and it is considered to be the gold standard to diagnose intrauterine pathology and has minimal intra-operative and post-operative morbidity. Objective: To evaluate the role of hysteroscopic guided endometrial biopsy in diagnosis of endometrial pathology in patients with unexplained recurrent implantation failure. Patients and methods: This prospective study was done on 100 patients attended SayedGalalHospital from March 2018 to September 2019, with history of recurrent implantation failure.      All patients were evaluated by full history taking include (Personal, Menstrual, Obstetric, Past), Full clinical examination (General, Abdominal, Local), transvaginal ultrasound, hysteroscopy and biopsy. Samples were collected to be examined for histopathology to detect any disease and to be tabulated for computerized analysis. Results: Of the 100 patients of infertility with a history of recurrent implantation failure undergoing endometrial biopsy guided by hysteroscopy, 48 (48%) showed normal findings and 52 (52%) showed abnormal findings: 28 were with normal hysteroscope but endometrial biopsy showed signs of chronic endometritis (28%),12 showed both abnormal hysteroscope and positive signs of chronic endometritis (12%), 7 showed endometrial polyp (7%) ,4 showed fine intrauterine adhesions (4%), and 1 showed cervical stenosis (1%). Conclusion: Hysteroscopy is of a great value in the evaluation and diagnosis of the endometrial pathology in patients with unexplained recurrent implantation failure.