This study was designed to assess the use of platelet-rich plasma (PRP) during primary total knee arthroplasty (TKA). The authors hypothesized that this would result in less blood loss and greater hemoglobin and hematocrit levels at discharge and would potentially decrease the length of hospital stay. Leukocyte rich PRP was used during the procedure and at wound closure. Two surgeons performed all procedures in a similar fashion. Two different TKA implants were used. Each surgeon used the same implant throughout the study. A limited medial parapatellar approach was used and drains were used at closure. No tranexamic acid preparations were used. Continuous passive motion machines were used in all patients during their hospital stay.