A 6.2 M glycerol solution was added directly to concentrated red blood cells before storage at — 80 C for at least two and one‐half years. The glycerol was removed from the thawed red blood cells by one of four different washing procedures, and the washed cells were stored at 4 C for an additional 24 hours before transfusion. Recoveryin vitrowas about 90 per cent, and the posttransfusion survival was about 85 per cent. The CPD anticoagulant maintained the oxygen transport much better than ACD during storage of the red blood cells at 4 C for one week prior to freezing. Results were similar whether glycerolized red blood cells were washed in reusable stainless steel bowls, disposable polycarbonate bowls, or collapsible disposable polyvinylchloride plastic bags. The composition of the wash solution had no significant effect on the posttransfusion survival or oxygen transport function. When the washed red blood cells were stored in a sodium chloride‐glucose‐phosphate solution at 4 C for 24 hours before transfusion, the 24‐hour posttransfusion survival and oxygen transport function was satisfactory. Freeze‐preservation of red blood cells with hematocrits of about 40 V per cent and postthaw storage at 4 C for 24 hours resulted in an accumulation of supernatant hemoglobin and extracellular potassium. At the time of transfusion, the red blood cells were concentrated by centrifugation, the supernatant medium was removed, and the hematocrit adjusted to 70