100 patients undergoing unilateral total knee arthroplasty were randomized to receive or not to receive a postoperative wound drain. Previous studies on this topic have been limited, and the authors sought to determine differences in blood loss, range of motion, complications, and the need for blood transfusions. The total blood loss was significantly different between the groups with patients who were treated with a drain experiencing greater blood loss. Patients who received the drain also required more blood transfusion; therefore, there was no evidence of an obvious benefit from treatment with a wound drain.