Three total knee arthroplasties were performed in two patients with severe hemophilia A and the patients were followed up for more than twelve months. One patient had both knees replaced. The ages at the time of operation were 22 years and 33 years. Pain and function were markedly improved, and average gain in range of motion was 23 degrees. Postoperative complications included hemarthrosis, and fever for a few days. The technical problems in treatment were formidable. Total knee arthroplasty appears to be a satifactory procedure in the treatment of disabling hemophilic arthropathy of the knee, but it should be perforemd only with strict hematological supervision. The surgeon should be prepared to treat many potential postoperative complications.