A patient with hemolytic disease of the newborn (HDN) due to maternal anti-Kpa alloimmunization is described. Although there are few reports in the literature, it appears that HDN due to anti-Kpa is often mild and transfusion therapy is rarely required. However, in this case, the baby's hemoglobin progressively decreased and on day 18 a blood transfusion was administered, but jaundice was not severe enough for exchange transfusion.