The aim of this article is to review the sonographic criteria of endometrial hyperplasia and define the cutoff value to indicate the completion of the endometrial biopsy due to its relationship with the risk of endometrial carcinoma. We report the case of a woman aged 47 with four years of vaginal bleeding characterized by menorrhagia, metrorrhagia, and hypermenorrhea being treated with oral contraceptives without improvement, and transvaginal ultrasound diagnosis of endometrial hyperplasia. For the diagnosis of endometrial pathology in postmenopausal women with vaginal bleeding, the authors recommend a cutoff value of endometrial thickness by transvaginal ultrasound of 4-5 mm with sensitivity of 98% and negative predictive value of 99% since higher values are closely related to endometrial carcinoma.