The clinical and radiographic outcomes of the cement-within-cement femoral stem exchange technique at revision hip arthroplasty were determined. Twenty-three revisions with a collarless polished double-taper stem design were prospectively monitored at up to 12 years. The most common indications for revision were recurrent dislocation and acetabular revision. Radiographic stem subsidence was measured by the Ein Bild Röentgen Analyse method. There was no stem re-revision and no radiographic loosening. Stem within cement subsidence, an intentional design feature of this stem, averaged 0.8 mm (range, 0-2 mm). The average subsidence was similar to that in primary hip arthroplasty. The excellent long-term results of cemented collarless polished taper stems for primary and revision hip arthroplasty can be extended even further by cement-within-cement exchange, which preserves the femur.