Autoimmune hemolytic anemia (AIHA) is a rare disease in which autoantibodies target red blood cells (RBCs), leading to anemia that ranges from no symptoms to severe life-threatening hemolysis. Little is known about the severity of anemia, blood transfusion efficiency and risk of transfusion-related reactions among hospitalized AIHA patients, especially in those with incompatible RBC transfusions.A retrospective study was conducted among hospitalized AIHA patients from January 2009 to December 2015 in a large tertiary care medical center in southwest China.A total of 450 AIHA hospitalized patients were recruited, of whom 97.3% had warm AIHA, 30.3% had primary AIHA, and 90.7% were treated with corticosteroids. On admission, approximately 3% of patients had an hemoglobin (Hb) <30 g/L, 34% had an Hb between 30 and 59.9 g/L, and 46% had an Hb ranging from 60 to 89.9 g/L. A total of 2509.5 U RBCs were transfused to AIHA patients, and 14 transfusion-related adverse reactions were recorded, without any hemolytic transfusion reactions. With an average transfusion trigger of 52.0 ± 9.3 g/L, 59.7% of the patients received RBCs, and 55.8% of the transfusions were viewed as effective. Least incompatible RBCs were given in 39% of the transfusions, but the transfusion efficiency did not significantly decrease with these incompatible blood transfusions (P = .253). Primary AIHA patients with a nadir Hb of approximately 40 to 50 g/L during their hospital stay had the highest rate of remission and did not require a different total number of RBC transfusions (P = .068) or length of hospitalization (P = .194) compared to other groups with nadir Hb values <30 g/L, ≥30 and <40 g/L, ≥50 and <60 g/L, and ≥60 g/L.One-third of AIHA patients suffered from severe anemia during hospitalization, and transfusions, even with incompatible RBCs, were safe and efficient. However, transfusion triggers between 40 and 50 g/L seemed to benefit the most patients by alleviating the RBC destruction caused by autoantibodies, and a restrictive transfusion strategy was beneficial in AIHA patients.