BACKGROUND Endometriosis is defined as the growth of ectopic endometrial tissue beyond the uterine cavity, and endometriosis on the uterine cervix is a rare variant. Although asymptomatic patients with cervical endometriosis or those with minor symptoms are treated conservatively, there are reports of life-threatening hemorrhage due to cervical endometriosis. Here, we report 2 cases of massive genital bleeding caused by cervical endometriotic cysts and we performed a literature review. CASE REPORT Case 1: A 32-year-old woman presented to our hospital due to massive genital bleeding on her 11th day of menstruation. An arterial hemorrhage in a cervical endometriotic cyst was suspected. As pressure hemostasis proved difficult, urgent uterine artery embolization (UAE) by interventional radiology was performed. Angiography during the UAE showed extravascular leakage from the branch of the left uterine artery. After embolization, hemostasis was achieved. No further genital bleeding was observed, and transvaginal ultrasound showed the cyst has continued to shrink for 9 months after the UAE with sequential dienogest, a progesterone receptor agonist, treatment. Case 2: A 43-year-old woman presented to our hospital with increasing massive genital bleeding after completing a 12-day course of 0.5 mg of norgestrel and 0.05 mg of ethinyl estradiol as a treatment for irregular intermenstrual bleeding. We suspected cervical endometriotic cyst rupture on imaging and performed an urgent laparoscopic total hysterectomy. In the excised uterine specimen, a cystic lesion that contained old, blood-like fluid was macroscopically observed in the cervix and was diagnosed pathologically as endometriosis. CONCLUSIONS Cervical endometriotic cyst rupture is rare; however, it should be kept in mind as a differential diagnosis when treating massive genital bleeding because urgent intervention is sometimes required to control the bleeding.