The temperature was measured using thermocouples in the bone-cement interface during cement curing in 30 total hip replacement operations. A modern technique was used, including lavage and precooled vacuum-mixed cement. The mean maximum temperature in the acetabulum was 43 (38-52) degrees C and in the femur 40 (29-56) degrees C. The use of a precooled femoral prosthesis did not affect the peak temperature.