In Mexico, aging has become the daily routine of millions. Total Knee Arthroplasty is a procedure that is doing more and more with satisfactory results and survival of the implant up to 20 years in 90%. The tourniquet is a useful tool to the orthopedic surgeons to minimize blood loss and make the placement of implants easier, because it enhances the vision of the surgical field. We report the results of 75 total knee arthroplasties performed in January 2007 to January 2010, in terms of bleeding, duration of procedure and Haemoglobin levels with and without tourniquet, the patients were distributed in 3 different groups, In group 1 the tourniquet was kept inflated until the placement of the femoral and tibial components, in group 2 the tourniquet was kept inflated until the wound dressing and finally in group 3 we did not use tourniquet. We performed hematic biometry 24 hours after surgery and if the patient's hemoglobin was less than 9.0 g/dl or the patient had low cardiac output symptoms, regardless of hemoglobin level, blood transfusion was indicated. The results demonstrate that there significant differences between the amount of blood loss among the 3 groups (1:1.157 ml, 2:709 ml, 3:1.493 ml) and surgical time (1:100, 2:110, 3:135). So that demonstrates that tourniquet use has a direct relation to blood loss and surgical time.