One hundred and fifty seven patients who underwent total knee arthroplasty were enrolled in this study to determine the effects of topically applied intra-articular tranexamic acid on blood loss and transfusion requirements. Patient’s wounds were randomized to be sprayed with 1 g of tranexamic acid in 50 mL of saline solution or simply 50 mL of saline solution. The results suggest that topical tranexamic acid reduces blood loss, the need for transfusions, length of hospital stay and cost. At a 3 month follow-up, patients’ functionality and the occurrence of adverse events were similar regardless of group allocation.