Intramural pregnancy with implantation in a previous caesarean section scar is probably the rarest location for an ectopic pregnancy. Little is known about its incidence and natural history. This rare condition may be accompanied by serious clinical events, such as rupture of the uterus and unrestrainable haemorrhage, which are sometimes treated with hysterectomy causing sterility. Most treatment choices are effectual, such as dilatation and curettage (D and C), excision of trophoblastic tissues using either laparotomy or laparoscopy, systemically administered methotrexate and, more recently, uterine artery embolization. Here, we report a case of an ectopic pregnancy that occurred in the scar of a previous caesarean section, which was diagnosed by transvaginal sonography.