A series consisting of 1,085 women with postmenopausal genital bleeding was investigated. The women were at least 45 years old and the time lapse from the last menstruation was at least one year. The bleeding was due to a malignant process in 28%. The majority of these patients had endometrial or cervical carcinoma. The ratio of these two conditions was 1:1. The median age of the patients showing malignant growth was clearly higher than the median age of those in whom the cause of bleeding was benign. The rate of malignant tumours as a cause of postmenopausal bleeding showed a definite rise with increasing age. Atrophic endometrium was the cause of bleeding in 20.5% of the patients. A hormonal reaction in the endometrium was involved in 15.5%, an endometrial or cervical polyp in 17.2%, cervicitis with erosion in 12.1%, and senile vaginitis in 1.3%. The incidence of other benign conditions was low. The aetiology of postmenopausal genital bleeding is discussed.