BACKGROUND Degenerative lumbar scoliosis (DLS) patients undergoing posterior long-segment spinal fusion surgery often require perioperative blood transfusions, and previous studies have reported that increased complications and additional costs accompany these transfusions. One method for decreasing transfusions is the administration of tranexamic acid (TXA). We sought to evaluate the costs and benefits of preoperative administration of 1 g of intravenous TXA, without maintenance, in DLS patients undergoing long-segment spinal fusion surgery. MATERIAL AND METHODS Patients who received TXA (TXA group) were compared with patients who did not receive TXA (NTXA group) with regard to blood loss, units of packed red blood cells (PRBC) transfused, hemostasis costs, and perioperative complications. The benefits and costs were estimated through analysis of the spending on NTXA and TXA patients, and were compared. The difference between the cost per patient in the 2 groups was designated as the net cost-benefit. Then, both groups were substratified into non-osteotomy and osteotomy subgroups for further analysis. RESULTS Of the 173 patients who met the inclusion criteria, 54 TXA patients had significantly reduced perioperative blood loss and total hemostasis costs compared with NTXA patients (n=119). In the group without osteotomy (n=72), TXA (n=13) reduced perioperative blood loss but did not significantly decrease PRBC units and hemostasis costs. However, in patients undergoing osteotomy (n=101), a remarkable net cost savings of ¥648.77 per patient was shown in the TXA group (n=41) (P<0.001). This was because patients undergoing osteotomy in the TXA group received fewer PRBC units (3.7 vs 5.7, P=0.001). CONCLUSIONS A single dose of TXA significantly decreased perioperative blood loss and total hemostasis costs for DLS patients undergoing osteotomy. Furthermore, TXA led to no additional net costs in patients without osteotomy.