Objective The aim of the present study was to investigate whether an innovative way of administering tranexamic acid (TXA), that is, injecting it retrogradely through the drain and clamping it for 1 h, can reduce postoperative bleeding after degenerative lumbar scoliosis surgery. Methods Sixty degenerative lumbar scoliosis patients who underwent posterior lumbar decompression with fusion of three or more levels were retrospectively enrolled and categorized into three groups (TXA, Gelfoam, and control groups). The demographic distribution, operative parameters, length and amount of Hemovac drainage, blood transfusion rate, length of stay, laboratory results (complete blood count and coagulogram), and the postoperative complications were collected and analyzed. Results The age of patients in the Gelfoam group was significantly younger than in the TXA and control groups (59.75 +/- 6.95 vs 66.10 +/- 8.80, P = 0.016 and 59.75 +/- 6.95 vs 67.90 +/- 5.33, P = 0.000, respectively). There were no significant differences in sex, body mass index, comorbid medical status, and operation level between each of the two groups. The three groups did not differ significantly in estimated blood loss during surgery, the mean red blood cell transfusion requirement during hospitalization, and the entire perioperative allogenic blood transfusion rate. The postoperative total blood loss and total drainage were lower in the TXA group than in the control group (1027.14 +/- 466.56 vs 1390.07 +/- 314.85 mL, P = 0.006; 322.20 +/- 187.32 vs 605.50 +/- 184.70 mL, P = 0.000, respectively). The length of drainage retention in the TXA group was significantly shorter than in the Gelfoam and control groups (46.10 +/- 9.00 vs 68.00 +/- 12.31 h, P = 0.000 and 46.10 +/- 9.00 vs 76.40 +/- 10.97 h, P = 0.000, respectively). The TXA and Gelfoam groups also had significantly shorter hospital stays than the control group (7.50 +/- 0.95 vs 9.80 +/- 2.44 days, P = 0.000, and 7.90 +/- 1.16 vs 9.80 +/- 2.44 days, P = 0.003, respectively). At discharge, the mean hemoglobin and hematocrit level were significantly higher in the TXA group compared with the control group (11.77 +/- 1.78 g/dL vs 10.67 +/- 0.94 g/dL, P = 0.002; 34.82 +/- 3.57% vs 31.79 +/- 3.85%, P = 0.014). No significant difference was identified with respect to prothrombin time, activated partial thromboplastin time, and D-dimmer among groups (P > 0.05). The three groups were comparable in wound problem incidences. Symptomatic deep vein thrombosis and pulmonary embolism were not observed in this study. Conclusion Topical injection of TXA retrogradely via a drain at the end of a degenerative lumbar scoliosis operation and clamping the drain for an hour can effectively decrease the postoperative blood loss and the length of hospitalization without increasing the complication rate.