In a retrospective cohort study the authors investigated the effectiveness and safety of perioperative tranexamic acid use in patients undergoing total hip or knee arthroplasty in the United States. They compared the outcomes of 20 051 patients who received tranexamic acid during hip or knee arthroplasty with 852 365 patients who did not, using data from 510 US hospitals. They found that tranexamic acid reduces blood transfusion with no increase in thromboembolic complications, acute renal failure, cerebrovascular events, myocardial infarction, in-hospital mortality, even after adjusting for patient characteristics and comorbidities. While their data provides incremental evidence of the effectiveness and safety of tranexamic acid in patients requiring orthopedic surgery further large adequately powered randomized trials are needed to, once and for all, conclude the safety of TXA for use in routine bloody surgical cases (where fibrinolyisis is stimulated) as outlined in the accompanying editorial by Ker and Roberts; Tranexamic acid for surgical bleeding. BMJ 2014;349:g4934.