100 patients undergoing a posterior lumbar interbody fusion procedure were randomized to receive a unit dose of intravenous tranexamic acid 15 minutes before skin incision (n=50) or normal saline (n=50). The outcomes of interest included operative time, blood loss, drainage volume, transfusion rate, events, coagulation and inflammatory markers. Biomarkers were measured at 1 and 4 days post-operation. The tranexamic acid group showed significantly less intra-operative, visible, and hidden blood loss, and less post-operative drainage compared to control. No differences in all coagulation and inflammatory biomarkers were observed between the two groups. The results of this study suggest that tranexamic acid is safe and effective for use in posterior lumbar interbody fusion surgery, however, larger, multi-centered trials are necessary to confirm the results.