In a radiographic study of 55 infants with an age-range of 27 weeks' gestation to 13 months post-term, the centre of the heart was positioned under the lower third of the sternum in 48 cases. In 4 infants the position was slightly more cephalad, but still below the lower half of the sternum. In 3 infants, the position was below the xiphisternal junction. Present guidelines for infant resuscitation should be revised in view of these findings.