Ultra-high-molecular weight polyethylene (UHMWPE) wear, debris-induced osteolysis is a frequent cause of failure of total hip arthroplasty. Metal-on-metal total hip arthroplasty eliminates the generation of UHMWPE particulate debris. Although the volumetric wear of a metal-on-metal articulation may be lower than a metal-UHMWPE articulation, the number of particles may be higher. Osteolysis can develop in response to metallic and UHMWPE debris. The following case of massive osteolysis associated with large amounts of cobalt-chrome wear debris shows adhesive and abrasive wear mechanisms, as well as wear caused by third-body cobalt-chrome debris and impingement of the femoral component against the rim of the acetabular cup, which led to failure of a metal-on-metal total hip arthroplasty.