Arteriovenous malformation of the uterus is rare. It is potentially lethal because profuse, uncontrollable bleeding may occur with diagnostic dilatation and curettage. Several cases of localized uterine arteriovenous malformation have been reported on. The condition should be considered during routine vaginal examination with pulsation and thrill in the vaginal fornices, even if there is a normal menstrual history, as in our patient. In our patient, pathologic examination of the uterus demonstrated for the first time an extensive, diffuse, tortuous arteriovenous anastomosis extending from the upper uterine segment down to the stroma of the exocervix. In such cases a thorough clinical and (if indicated) radiologic evaluation should be done before curettage, or even cone biopsy, to avoid possible massive hemorrhage.