Few studies have been conducted to investigate the wear resistance of nanoparticle-reinforced graphite ductile irons. In this research, graphite ductile irons with a trace amount of TiC-TiB2 nanoparticles are fabricated. The influences of nanoparticles on the microstructure and wear properties of as-cast graphite ductile irons are studied. It is found that the presence of nanoparticles can effectively refine the graphite nodules and substrate in the matrix, which can be associated with the heterogenous cores of nanoparticles during the phase transformation. In sliding wear tests, the addition of nanoparticles provides benefits in reducing the wear rate of graphite ductile irons under various test conditions. The improvement becomes more pronounced when increasing the concentration of nanoparticles. Additionally, it is observed that the wear mechanisms are dominated by adhesive wear, abrasive wear and oxidative wear. The excellent wear properties can be attributed to the increased hardness of substrate, separation of contacting areas, inhibition of plowing and resistance to plastic deformation. The findings in this study are applicable to the preparation and application of novel graphite ductile irons with enhanced wear resistance.