Displacement of a polished femoral stem from its cement mantle occurred during an attempted reduction of a dislocated total hip arthroplasty. This might be related to the geometry and surface finish of the stem, as well as the wedge-shaped and highly polished design. The stem became displaced when the femoral head impinged the acetabular margin during the reduction of the dislocated prosthesis. Surgeons need to be aware of this complication associated with using a polished femoral stem. This can be avoided by cementing over the shoulder of the stem as well as careful reduction under fluoroscopic control.