Previous studies have shown that, compared with standard electrocautery, a bipolar sealer reduces tissue damage and smoke production during surgery. We conducted a multicenter, prospective, randomized study to compare a bipolar sealer with standard electrocautery for hemostasis. Sixty-nine primary total knee arthroplasties were performed. Cohorts were evaluated for intraoperative and postoperative blood loss, blood transfusion requirements, postoperative hemoglobin and pain levels, length of hospital stay, range of motion, and Knee Society scores. Amount of blood loss and decrease in postoperative hemoglobin were significantly lower in the bipolar sealer group than in the standard electrocautery group. Need for autologous blood transfusions was decreased in the bipolar sealer group compared with the electrocautery group. There were no between-groups differences in clinical knee scores. The bipolar sealer was an effective coagulation alternative for total knee arthroplasties in reducing blood loss and transfusion requirements without affecting clinical outcome.