In this meta-analysis twenty-nine randomized controlled trials were included to assess the effect of tourniquet application (n=1258) in primary total knee arthroplasty compared to no tourniquet (n=1254). Outcomes of interest included range of motion in knee flexion and extension, knee society score, hematocrit levels, oxford knee score, knee circumference, hospital stay, bone cement mantle thickness, and complications. No significant differences were apparent between the tourniquet versus no tourniquet groups with regard to draining volume, total blood loss, transfusion rate, hemoglobin change, risk of deep vein thrombosis, and risk of all other complications. Bone cement mantle thickness and length of hospital stay favored no tourniquet use, whereas intraoperative blood loss and operative time favored the tourniquet group. Tourniquet use resulted in greater postoperative pain, decreased range of motion in flexion and extension, decreased function, and increased swelling.