Abstract: A prosthesis holding system is provided for holding and positioning a prosthetic cup during surgery. The rim of the cup includes opposed inwardly and outwardly facing recesses. A holder includes an elongated rod having a shoe at one end. The shoe includes a tab for engaging the inwardly facing recess in the rim of the cup. The shoe further includes a threaded aperture alignable with the outwardly facing recess in the rim of the cup. A clamping screw is engageable with the threaded aperture and is further engageable with the outwardly facing recess in the rim of the cup. Tightening of the clamping screw securely holds the cup without interfering with either the interior concave surface of the cup or the exterior convex surface of the cup, to enable efficient implantation of the cup in a patient during surgery.