Background: Endometritis is a severe complication occur- ring after the termination of pregnancy. It occurred at variable rates after first-trimester abortion. Variable diagnostic methods with variable accuracies are reported. Aim: to detect endometritis after medical and surgical termination of first-trimester abortion using different diagnostic methods. Methods: This cross-sectional study was conducted at the obstetrics and gynecology department at Fayoum university from May 2018 to February 2020. The study recruited 100 women divided into two groups. Groups A and B included fifty patients who had medical and surgical evacuation of first-trimester abortion, a history of unexplained delayed conception for at least one year, and recurrent miscarriage. Recruited women were subjected to history taking, laboratory investigation, pelvic examination, transvaginal ultrasonography, and endometrial sampling. An office hysteroscopy was arranged during the follicular phase of the menstrual cycle. This was followed by two endometrial samples using the Pipelle (Pipelle de Cornier, CCD). Results: There was an insignificant difference between group A and group B regarding H&E examination by Hysteroscopy and Pipelle and immunostaining examination by Pipelle (P-value > 0.05);. At the same time, it points to a statistically significant difference between group A and group B regarding Immunostaining examination by Hysteroscopy (P-value =0.029). Endometritis was more significantly evident in Immunostaining examination by hysteroscopy in group B than in group A (40% vs. 20%, respectively). The diagnostic accuracy of Immunostaining examination by hysteroscopy was significant (P-value = 0.028). Conclusion: Endometritis occurs significantly after surgical termination of first-trimester abortion. Hysteroscopic guided biopsy followed by immunohistochemistry was associated with high diagnostic accuracy for endometritis.