At the end of this short study we have to sum up our views about the use of the acrylic prosthesis for arthroplasty of the hip. Some fatalities and a proportion of bad or poor results make this operation one to be undertaken only by surgeons well trained in the surgery of the hip and only on patients who really need it. However, the tolerance of the tissues to acrylic resin and the fixation of the stem in the neck of the femur promise to be lasting. We know that a much longer time is necessary to confirm these general statements, which proceed from an experience of only five years and the study of six hundred cases.