The cases of 175 consecutive patients who had intraoperative autologous transfusion during revision total hip arthroplasty, an elective operation on the spine, repair of trauma to the spine, or open reduction of a fracture of the acetabulum were reviewed to evaluate the applicability of this technique in orthopaedic operations. A separate group of forty-one consecutive patients who had open reduction of a fracture of the acetabulum or the spine before the introduction of the autotransfuser was reviewed and compared with the group that had autotransfusion. An autologous blood predeposit program was used for twenty-five of fifty-two patients who had a procedure on the hip and for fifty-one of fifty-five patients who had an elective procedure on the spine. The mean rate of red blood-cell salvage using the autotransfuser was 60 per cent over-all. The mean transfusion requirements were significantly less (p less than 0.001) in all groups of patients in whom the autotransfuser was used. Use of the autotransfuser reduced the mean requirement for banked blood in patients who had a fracture of the acetabulum from 3.8 to 2.3 units per patient, and significantly reduced the mean need for banked blood in individuals who had trauma to the spine from 2.7 to 1.8 units per patient (p less than 0.01). The use of prebanked autologous blood further reduced the mean requirement for homologous blood from 2.4 to 0.8 unit per patient in those who had revision total hip arthroplasty (p less than 0.005), and from 3.6 to 0.4 unit per patient in those who had an elective procedure on the spine (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)