This report deals with a microangiographic study of 69 human fetal spinal cords, as well as 19 cords from infants and children. The youngest fetus was 10 weeks old. The characteristic "hairpin" arrangement of the thoracic and lumbar radiculomedullary arteries is already evident in all our fetuses, including the smallest. The anterior spinal artery shows a straight course in the younger fetuses to become tortuous in a number of older fetuses, term babies and younger children up to 2 years. The so-called "watershed areas" found in the anterior spinal artery in the adult are not clearly recognizable in the pre-birth cord.