Transfusion-related acute lung injury (TRALI) is an underdiagnosed serious complication of blood transfusion characterized by the rapid onset of respiratory distress, hypoxia, and noncardiogenic pulmonary edema during or soon after blood transfusion. The presence of anti-HLA and/or antigranulocyte antibodies in the plasma of donors is implicated in the pathogenesis of TRALI. We report 2 cases of TRALI that were caused by designated blood transfusion between mothers and their daughters; one in a 4-month-old girl who received designated packed RBCs donated by her mother and the second in a 78-year-old mother who received blood from her daughter. In both cases, examination of mother's serum revealed panel-reactive cytotoxic HLA antibodies. It is most likely that the mothers were sensitized from earlier pregnancy and produced HLA antibodies against the daughters' paternally derived HLA antigens. Designated blood transfusion between multiparous mothers and children might add an additional transfusion-related risk owing to the higher likelihood of the HLA antibody-antigen specificity between mother and child.