Abnormal uterine bleeding (AUB) is a common medical problem, with a direct influence on women’s quality of life, utilization of health care resources, and costs. AUB in women older than 40 years and especially in postmenopausal women requires a prompt and efficient evaluation, mainly to exclude the presence of malignant or premalignant lesions of the endometrium. Cancer of the endometrium is the most common gynecologic malignancy, with an incidence in the United States of more than 60,000 cases and mortality estimated at 10,000 women annually. This article outlines the role of transvaginal ultrasonography in the evaluation of cases of AUB.