Patients undergoing spine surgery are possibly exposed to severe blood loss so that different methods have been developed to face this problem. Allogeneic transfusion can compensate the anemia but the occurrence of transfusion-related infections, the refuse secondary to cultural or religious beliefs, the limited availability, are solid reasons for evaluating possible alternatives. Predeposit programs before surgery and plasmapheresis or intentional isovolemic hemodiluition during surgery are largely adopted solutions. Particularly, predeposit programs for autologous blood transfusions have become standard in association with elective spine surgery1 and has shown to reduce the number of allogeneic transfusions2. Because the need for blood transfusion in patients undergoing spine surgery is difficult to predict due to variety of surgical procedures, various studies have been attempted to determine guidelines for its use3-11. In last decades interbody spinal fusion procedure with a transforaminal (TLIF) or a posterior (PLIF) approach has gained popularity, with indications including spinal stenosis, instability, degenerative disc disease, spondylolisthesis, spondylolysis, and bilateral disc herniation12-14. Even if these procedures are performed by posterior approach alone, the operation time is longer than posterior fusion and consequentially more blood loss can be expected. Based on these preliminary remarks specific guidelines should be proposed to decide if and how many autologous units should be collected according to expected procedure.