The quality of transfused blood is especially important during cardiac surgery, and red blood cell viability and function may be adversely affected during perfusion through the artificial blood oxygenator used during extracorporeal bypass. In this study, we administered 10 ml aliquot autotransfusions of rejuvenated red blood cells to 13 healthy volunteers after perfusion through an infant bubble oxygenator for one to three hours. Twenty‐three other volunteers received rejuvenated red blood cells that had not been perfused. The red blood cells were biochemically modified after they had reached their outdating period, a process used to increase 2,3 DPG and ATP levels and improve oxygen transport function. The rejuvenated red blood cells were frozen with 40% W/V glycerol, stored frozen at ‐80 C for about 3 months, thawed, washed, and stored in a sodium chloride‐glucose‐phosphate solution at 4 C for as long as three days. Freeze‐thaw recovery was about 97 per cent, and freeze‐thaw‐wash recovery about 90 per cent. Twenty‐three units were transfused after 1 to 3 days of post‐wash storage, and 13 units were perfused through an infant bubble oxygenator for as long as three hours before transfusion. The 24‐hour posttransfusion survival values were about 80 per cent and oxygen transport function was either normal or improved whether or not the units were perfused