The results of a rhesus prevention programme are reported, confirming that rhesus immunization is a preventable condition. The procedure of foeto-maternal transfusion using the KJeihauer technique did not appear to allow the detection of high risk cases. It is argued that anti-D immunoglobulin may be administered without the prior determination of foetal blood group and the detection of foetal red cells in the maternal circulation and that all rhesus-negative women should be given passive immunization as a routine shortly after delivery.