Although fetomaternal hemorrhage (FMH) of more than 30 ml is relatively rare, massive FMH can cause severe neonatal anemia and even fetal death. We report 2 cases of severe neonatal anemia due to FMH. The key features leading to early diagnosis were fetal monitoring, clinical and laboratory findings of anemia, and a negative Coombs' test. Diagnosis was confirmed by a rapid Kleihauer-Betke (KB) test. Blood transfusion was performed for both of the neonates, with rapid clinical and hematological improvement subsequently observed.