The aim of this study is to assess the effectiveness of pipelle in sampling diagnostic material from the uterine cavity and determining clinical factors, which may affect its effectiveness.The retrospective analysis included 312 patients who underwent pipelle biopsy because of various indications. Evaluated factors which may affect the effectiveness of this method were: types of indications for the procedure, age, BMI, anteflexion or retroflexion of the uterus, presence of uterine fibroids, miscarriages, natural deliveries, deliveries in general.In 259 (83.01%) cases sampled material allowed for a histopathological diagnosis. In 53 (16.99%) of the women we failed to sample tissue material from the uterine cavity. Indications for the procedure, BMI, age and menopausal status were factors of potential impact on the diagnostic effectiveness (p 28), post-menopausal women, women over 55 years of age and where biopsy was performed for indications other than abnormal uterine bleeding. On the other hand, pipelle shows clearly the highest effectiveness in sampling diagnostic material from the uterine cavity in young women (< 45 years of age), menstruating women, women with normal body weight or underweight (BMI < 23) and abnormal uterine bleeding.Choosing a pipelle as an endometrial biopsy method should consider the indications, BMI, age and menopausal status. Omission of these factors can increase non-diagnostic outcomes resulting in necessity of repeated biopsies, the risk of complications and increases the costs of health care system.