Objective: To assess the impact of pre-arthroplasty diagnosis on the efficacy of TXA. Methods: A cohort study of patients underwent primary unilateral THA during two periods (2011 to 2012 without tranexamic acid, 2012 to 2013 with 10 mg/kg tranexamic acid) was conducted. Outcomes of blood loss and red cell blood transfusion rate were compared in different subgroups according to stratified analysis of pre-arthroplasty diagnosis. And logistic regression analysis was performed to assess the effects of different diagnosis on transfusion. Results: A total of 827 patients were included. Use of TXA produced a statistical significance in total blood loss (0.998 L vs 1.383 L, P<0.001) and transfusion rate (6.72% vs 20.85%, P<0.001), with no increase of thromboembolic events. Pre-arthroplasty diagnosis was not a risk factor for postoperative transfusion (P>0.05) independent of preoperative hemoglobin (OR=4.284, P=0.002), hematocrit (OR=2.731, P=0.022) and TXA use (OR=0.243, P<0.001). In quantitative terms of transfusion, the results supported a higher efficacy in osteonecrosis of femoral head (OR=0.213, P=0.001), followed by osteoarthritis (OR=0.265, P=0.016) and development dysplasia of hip (OR=0.311, P=0.002). Conclusion: An intravenous dose of 10 mg/kg TXA was effective and safe to reduce blood loss and transfusion in patients undergoing primary total hip arthroplasty. Even the blood loss varied among disease, pre-arthroplasty diagnosis was not the risk factor for postoperative transfusion. And intravenous TXA use may produce a higher efficacy in the patients with osteonecrosis.