A total of 130 cordocenteses, including 96 intravascular fetal blood transfusions, were performed in 21 pregnancies complicated by red cell isoimmunization. Transfusions were commenced at 18–34 weeks’ gestation and repeated up to 7 times, at 1- to 4-week intervals. The volumes of transfused blood were 5–150 ml, the haematocrits 62–88 % and the rate of transfusions 1–15 ml/min. The pretransfusion fetal haematocrits were 5–34% and the posttransfusion ones 28–60%. Final transfusions were given at 32–36 weeks’ gestation. Of the 21 pregnancies, 18 delivered at 31–39 weeks and 3 are continuing; 1 baby was stillborn and 17 are alive and well.