PURPOSE: We wanted to analyze the effects of tourniquet pressure on the postoperative thigh pain and blood loss of patients who undergo total knee arthroplasty. MATERIALS AND METHODS: This prospective randomized study focused on one-hundred sixty-one unilateral total knee arthroplasties that were done with using a tourniquet. The tourniquet pressures were 300 mmHg in group I (seventy-four cases) and 100 mmHg higher than the systolic blood pressure in group II (eighty-seven cases). We analyzed the postoperative thigh pain with using a visual analog scale (VAS), and we assessed the hemoglobin levels and the hematocrits. RESULTS: The incidence of postoperative thigh pain in group II was statistically lower than that of group I. The intensity of the postoperative thigh pain of group II was lower than that of group I at both 6 hours and 72 hours after surgery. There were no statistical differences in blood loss between the two groups. CONCLUSION: Using a tourniquet pressure of 100 mmHg above the systolic blood pressure during total knee arthroplasty can reduce the postoperative thigh pain. When comparing the above technique with a TKA using 300 mmHg of tourniquet pressure, there was no statistically significant difference of the postoperative blood loss.