Endometrial polyps are the most common pathology of the uterine cavity. They are more frequent in postmenopausal women. The polyps can be asymptomatic or cause irregular spotting and uterine bleeding. Reproductive organ ultrasonography is a noninvasive diagnostic procedure to make a preliminary diagnosis of endometrial polyp. Diagnostic and treatment procedures in polyps include hysteroscopy (preferred) and D&C procedures. The study analyzes medical history of patients of the Gynecology and Oncological Gynecology Clinic, The Military Institute of Medicine in Warsaw, who underwent minihysteroscopy procedure due to suspected uterine cavity pathology in the years 2013–2016. Analysis of the results of hysteroscopic visualization and histopathological examination of tissue extracted during the procedure showed high sensitivity of hysteroscopy in detecting endometrial polyps. In the group of postmenopausal females, it was about 97.3% and for premenopausal females about 91.2%. Hysteroscopy specificity was quite low in both groups – about 51%. In conclusion, hysteroscopy should be a gold standard in the diagnosis of endometrial polyps, both in the premenopausal and postmenopausal women.