Forty-five cemented total hip replacements in thirty-eight patients who were less than fifty years old were followed with physical examinations and radiographs for five to eleven years (average, 7.3 years) after surgery. The average age of the patients at the time of surgery was 40.7 years. The average Iowa hip rating at follow-up was 91.9 points (range, 58 to 100 points). No surgical deaths, infections, or dislocations were encountered. All of the patients had been repeatedly advised to avoid running, jumping, heavy labor, and lifting more than forty pounds (eighteen kilograms). Revision of a prosthetic component was necessary in four hips (8.9 per cent); all of the revisions were successful. Radiolucent lines were seen about the acetabular components of thirty-one hips but in only three (6.6 per cent) were these judged to be progressive bone-cement demarcation lines. Only one of those three hips was symptomatic. Three hips (6.6 per cent) also had subsidence of the femoral component into the femoral canal, but only one hip was symptomatic. Resorption of the medial aspect of the proximal end of the femur was seen in five hips, the maximum resorption being three to five millimeters. I have concluded that cemented total hip arthroplasty can give acceptable results in patients who are thirty to fifty years old, and that the result can be reasonably long-lasting if the patients are willing to avoid strenuous activity.