Excellent wear resistance is an important feature of orthopedic implants. However, although pure polyetheretherketone (PEEK) is outperformed by carbon fiber-reinforced PEEK (CF-PEEK) for stability and durability under laboratory conditions, it is not clear whether CF-PEEK should be preferred in all real-world applications. Results indicate that, under dipalmitoylphosphatidylcholine (DPPC) lubrication, the wear rates of PEEK are 35%–80% lower than the wear rates of CF-PEEK for different implant materials, speeds, loadings, and DPPC concentrations. Molecular dynamics calculations confirm that DPPC self-assembles on the PEEK surface to form an easily adsorbed continuous phospholipid lubricating film. In contrast, the carbon fibers on the CF-PEEK surface hinder the formation of the protective DPPC film and the CF-PEEK surface is thus subject to faster wear.