Cesarean scar ectopic pregnancy is a complication in which an early pregnancy implants in the scar from a previous cesarean delivery. This condition presents a substantial risk for severe maternal morbidity and mortality because of challenges in securing a prompt diagnosis. Ultrasound is the primary imaging modality for cesarean scar ectopic pregnancy diagnosis, although a correct and timely determination can be difficult. Surgical, medical, and minimally invasive therapies have been described for cesarean scar ectopic pregnancy management, but the optimal treatment is unknown. Patients who decline treatment of a cesarean scar ectopic pregnancy should be counseled regarding the risk for severe morbidity. The following are the Society for Maternal-Fetal Medicine recommendations: we recommend against expectant management of cesarean scar ectopic pregnancy (GRADE 1B); we suggest that operative resection (with transvaginal or laparoscopic approaches when possible) or ultrasound-guided uterine aspiration be considered for the surgical management of cesarean scar ectopic pregnancy and that sharp curettage alone be avoided (GRADE 2C); we suggest intragestational methotrexate for the medical treatment of cesarean scar ectopic pregnancy, with or without other treatment modalities (GRADE 2C); we recommend that systemic methotrexate alone not be used to treat cesarean scar ectopic pregnancy (GRADE 1C); in patients who choose expectant management and continuation of a cesarean scar ectopic pregnancy, we recommend repeated cesarean delivery between 34 0/7 and 35 6/7 weeks of gestation (GRADE 1C); we recommend that patients with a cesarean scar ectopic pregnancy be advised on the risks of another pregnancy and counseled regarding effective contraceptive methods, including long-acting reversible contraception and permanent contraception (GRADE 1C).