Perioperative patient optimization can minimize the need for blood transfusions in patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA). The purpose of this study was to determine predictors and complications of transfusions. This retrospective review analyzed 1795 patients who underwent primary THA and TKA at our institution between January 2011 and December 2012. Of the 1573 patients ultimately included the rates of transfusion were 9.27% in TKA and 26.6% in THA. Significant predictors for transfusion include: preoperative hemoglobin, age, female gender, body mass index, creatinine, TKA, operating room time, operative blood loss, and intra-operative fluids. The DVT rate was comparable, but deep surgical site infection rate among transfused patients was 2.4% compared to 0.5% in non-transfused patients (P = 0.0065). Copyright © 2014 Elsevier Inc. All rights reserved.