Red cell unexpected alloantibodies can be present in healthy donors who were either transfused previously or pregnant previously. Presence of irregular erythrocyte alloantibodies can occasionally cause severe transfusion reaction if a large amount of plasma or whole blood is transfused as in massive transfusions and in pediatric patients. Here we are presenting a case report of a donor who had red cell alloantibody. The purpose of highlighting this case report is to know the significance of detecting irregular erythrocyte antibodies in healthy donors.