Thigh pain following tourniquet application is a common patient complaint in the early postoperative period following total knee arthroplasty. Postoperative thigh pain was evaluated in 28 consecutive simultaneous bilateral total knee arthroplasty patients between April 1996 and October 1996. A prospective, double-blind, randomized clinical trial was performed. Tourniquet pressure of 350 mmHg was used on 1 thigh (thigh 1) and 100 mmHg plus systolic blood pressure on the other (thigh 2). A scale of pain (no pain, mild, moderate, or severe) was applied on the first, second, and third days, as well as 2 and 6 weeks after surgery. There were 16 men and 12 women with a mean age of 72 years (range, 55-85 years). The mean tourniquet time was similar in both groups (thigh 1 = 23 minutes, thigh 2 = 22 minutes). The mean tourniquet pressure in thigh 2 was 230 mmHg (range, 212-260 mmHg). There was a statistically significant difference in thigh pain on the first (P = .01), second (P = .01), and third (P = .001) postoperative days between both groups, with more thigh pain on the 350 mmHg side. At 6 weeks after surgery, the difference in thigh pain was gone. For total knee arthroplasty, using the tourniquet at a pressure of 100 mmHg above the systolic blood pressure is recommended. This is adequate to provide a bloodless field and will result in a less unpleasant postoperative period.