An unusual case of placenta accreta diagnosed before delivery and managed conservatively is reported in a third-trimester pregnant woman with no past obstetric history. Ultrasound revealed a large echo-poor area where the decidual interface was absent. Uterine vessels immediately under and around the placental abnormal insertion site appeared dilated. In one area, where the myometrium could not be identified at all, the basal plate of the placenta appeared to float inside uterine vessels. A Cesarean section was performed at term and after partial delivery of the placenta a wedge resection of the accreta area was made. Brisk bleeding was controlled by rapid reconstitution of the myometrium. It is suggested that non-previa placenta accreta can be diagnosed antenatally in a low-risk population using gray-scale ultrasound imaging and enabling, in most cases, conservative management.