Polyether ether ketone (PEEK) is a commonly used engineering plastic but has poor friction and wear properties when compared to those of ultra-high-molecular-weight polyethylene (UHMWPE), whereas UHMWPE has good tribological properties but relatively weaker mechanical strengths. An optimum combination of these two materials is expected to have both sides’ goodness without adverse effects to a certain extent. Adding an optimum amount of PEEK powder filler into UHMWPE to form composite has shown better friction, wear and compressive strength properties. The mechanism of wear resistance improvement is found largely due to counterface transfer film but less because of the filler strengthening effect. Adding PEEK could improve the compressive strength of the composite due to high hardness of PEEK particles.