This study investigated the production, characterization, mechanical and tribological performance of surface-modified cow bone powder-reinforced composites. The primary goal was to increase the tribological and mechanical performance of sustainable and cleanly produced composite materials. It was determined that the surface-modified bone powder reinforcement increased the mechanical, thermal, and wear resistance of the polymer. The best surface modification method was determined as silanization. It reduced the friction coefficient and weight loss by 16.60% and 40.0%, respectively, according to the main factor analysis. In addition, it increased the glass transition temperature by 45.54%, crystallization by 2.93%, hardness by 2.70%, and tensile strength by 9.26% compared to the unmodified bone powder reinforcement. Highlights: Surface-modified cow bone powder-reinforced composites were produced and characterized. The tribological and mechanical performance of the composites was investigated comprehensively. Surface-modified composites improved the wear resistance. Surface-modified composites improved the thermal resistance and mechanical properties. The best surface modification method was found to be silanization.