Wear debris has been observed in shoulder arthroplasties that use an ultrahigh-molecular weight polyethylene (UHMWPE) glenoid component, and the biologic response to this debris contributes to aseptic loosening of the implant. The objective of this study was to assess the wear and particle morphology of a cross-linked UHMWPE prosthetic glenoid. To our knowledge, this is the first time a simulator with kinematic considerations for assessing wear has been used in a shoulder model. Shoulder wear testing was conducted on 2 groups of glenoids (n = 3 in each group) by use of an orthopaedic joint simulator to create worst-case scenario motions. One group was manufactured from conventional UHMWPE. The second was manufactured from 50-kGy cross-linked UHMWPE. The resulting wear rates for the conventional and cross-linked glenoid components were 46.7 +/- 2.6 mg/million cycles and 7.0 +/- 0.4 mg/million cycles, respectively. Particles isolated from the 2 groups showed similar morphologies; however, the calculated osteolytic potential of the cross-linked glenoid was significantly lower. The results of this study support the use of cross-linked UHMWPE glenoids in clinical applications.