A patient suffering from reflux oesophagitis under treatment with ranitidine continued the treatment throughout her pregnancy (450 mg/die). The ranitidine was delivered into the maternal blood serum and the amniotic fluid up to the 17th week of pregnancy, then into the blood serum of the maternal and umbilical cord immediately after delivery, and into the serum of the newborn 24 hours after birth. The authors report the values and comment on them.