Adenomyosis is defined as the invasion of the basal endometrium (stroma and glands) into the underlying myometrium. It may lead to abnormal uterine bleeding (AUB), pelvic pain, and infertility. The definitive treatment is hysterectomy. Some conservative measures have been used in patients willing to procreate. Ulipristal acetate is a selective progesterone receptor modulator used to treat AUB caused by leiomyomas. This is a systematic review on the use of ulipristal to treat adenomyosis. Eight eligible articles were retrieved from PubMed, SCOPUS, and Cochrane Library. Only one randomized clinical trial was published until date concerning this matter. It seems that ulipristal acetate induces partial or complete remission of AUB caused by adenomyosis, but the evidence concerning its effect on pelvic pain and the radiologic findings of the disease is conflicting. Nevertheless, given the paucity of data, it is still preliminary to draw any conclusion about the subject.