This case report shows the successful use of early medical treatment of ectopic intramural pregnancy with ultrasound-guided laparoscopic methotrexate (Mtx) injection. A 28-year old woman, gravida 1, para 0, with a history of laparoscopic cystectomy of an endometriotic cyst of the left ovary two years ago was referred to the present clinic. The patient was treated with IVF-ET because of tubal occlusion. Transvaginal ultrasonography showed an ectopic gestational sac (GS) with presence of yolk sac and embryo with a heartbeat in the posterior uterine wall, completely surrounded by myometrium. The authors successfully treated her with US-guided injection of Mtx into the GS cavity by laparoscopic approach.