Blood transfusions are frequently necessary for patients having open heart surgery. Although autologous blood is free of such risks as transfusion-transmitted diseases, the safety and effectiveness of autologous donations by cardiac patients are debated. We analyzed the records of 291 consecutive patients undergoing elective open heart surgery. One hundred seven (36.8%) donated between 1 and 6 U of autologous blood (mean, 3.0 +/- 1.5 U) before undergoing surgery. First-time elective coronary artery bypass surgery was the most common indication for autologous donation (90.6% of autologous donors). Problems following donations were infrequent (2 of 326 donations) and without long-term consequences. Among patients having coronary artery bypass surgery who donated autologous blood, 27% required homologous blood transfusions as compared with 82% of other patients undergoing the same procedure. We conclude that autologous blood donations are safe for patients with cardiac disease and effective in significantly reducing homologous blood needs in patients undergoing elective coronary artery bypass surgery.