Introduction. Accuracy of transvaginal sonography (TVS) is substantial as the first-line approach of intrauterine pathology diagnostics. However, TVS has some limitations and factors that reduce its accuracy have not been definitively determined.Aim. To evaluate the diagnostic accuracy of echography in intrauterine pathology and identify factors affecting it. Materials and methods. The study included 250 women who underwent hysteroscopy with endometrial biopsy: 128 with endometrial polyps (EP), 33 with endometrial hyperplasia (EH), 28 with chronic endometritis (CE) and 60 women without endometrial pathology.Results. The sensitivity and specificity of ultrasound in diagnosis of EP was 64.8% and 77.9%, respectively, EH – 64.7% and 89.8%, CE – 39.3% and 90.1%. Cumulative intrauterine pathology’s sensitivity reached 94.7%, and the specificity – 15.0%, which indicates a significant amount of false positive results. The lowest accuracy was in CE, EP less than 0.6 cm and in the absence of abnormal uterine bleeding.Conclusions. TVS has limitations in verifying a specific diagnosis and characterized by both hyper- and hypodiagnosis. The clinician should take into account the size of the EP and the presence of symptoms for choosing optimal management.