We treated two patients with corneal allograft rejections, both of which occurred within a few weeks after administration of multiple blood transfusions. In the first case, a patient with a graft that had been previously clear for 11 years developed severe endothelial rejection six weeks after transfusion of ten units of packed red blood cells. In the second case, a graft that had been clear for 14 months irreversibly rejected two weeks after transfusion of six units of packed red blood cells. These cases suggest that multiple blood transfusions may be a risk factor for corneal allograft rejection.