HE PRACTICES of autologous transfusion and directed donation have become so com monplace in transfusion medicine that a review of these subjects may be most useful in highlighting unresolved issues. Most of these remain points of contention because of a lack of substantial data to address underlying issues. By reconsidering that which is known and that which is yet to be deter mined in these rapidly evolving areas of transfu sion medicine, a further appreciation of the appro priate roles of these two methodologies may be gained. SAFETY IN TRANSFUSION The primary motivation behind the recent up surge in interest in autologous transfusion and di rected donations is transfusion safety. The defini tion of safety has different elements for different participants in the transfusion process. For the pa tient, risk-free medical therapy is the goal-albeit unrealistic-and any steps that could be taken to eliminate, reduce, or control risks are sought, sometimes with intense perseverance. For physi cians, limitation of risk is also important, although avoidance of litigation may be an important factor as well. For blood collection agencies, these con cerns must be melded with the overall mission of its operation, which, until recently, may have been defined primarily in terms of volunteer homolo gous blood products. The ancient dictum, primum non nocere, con tinues to be of practical utility in transfusion med icine. Therapies should be applied in a judicious, circumspect manner so that their expected benefits outweigh their potential risks. The understanding of fa<::tors to be entered into the transfusion equa tion of risks and benefits has undergone dramatic changes in the last 5 to 10 years. The messages of transfusion medicine consultations-transfuse