A case of adenosarcoma of the uterus in a 59-year-old woman is here reported. Adenosarcoma is a low malignant potential tumor with a benign glandular and a malignant stromal component. The treatment is usually hysterectomy with bilateral salpingo-oophorectomy. Debated is the usefulness of adjuvant chemotherapy, while radiation treatment is not beneficial. Long term follow-up is necessary for these patients because of high recurrence risk, mostly in cases with myometrial invasion.