The study evaluated the accuracy of preoperative endometrial biopsy (EB) and causes of abnormal uterine bleeding (AUB) in patients undergoing hysterectomy according to the PALM-COEIN classification. The average age of the patients was 48.2 ± 6.9 years and 28.0% had postmenopausal bleeding. The most frequent were structural causes (PALM), especially leiomyomas (35.5% isolated, 59.8% overall). EB had high specificity but low sensitivity, for example for atypical endometrial hyperplasia and higher 22.2% sensitivity and 99.6% specificity (AUC 0.609) or for endometrial polyps 30.6% sensitivity and 83.0% specificity (AUC 0.568). The overall agreement between EB and final pathology was low to moderate (Kappa coefficient). EB is good for excluding pathologies, but insufficient for detecting focal lesions. EB results should be supported by imaging methods when suspected.