The use of autologous blood transfusion to decrease blood bank requirements and improve coagulation parameters during cardiac surgery is still controversial. This study was undertaken to re-evaluate 3 methods of autologous blood transfusion. Before bypass, 13-15% of the patient''s estimated blood volume was removed and stored with either CPD [citrate-phosphate-dextrose] or heparin at room temperature and returned via a peripheral vein after bypass. All patients had significant abnormalities in their PTT [partial thromboplastin], PT [prothrombin time] and platelet counts after bypass. Heparinized autologous blood removed from the vena cava cannula was the only technique which significantly improved the PTT and platelet count. Total blood bank requirements were significantly less for the autologous blood groups than for controls. There was a saving of 18% in banked blood requirements. Fresh frozen plasma and platelets were not found to be routinely needed during cardiac surgery.