In this study, solid-state mechanochemical milling was investigated as a viable strategy to produce high performance blends composed of polypropylene (PP) and ground tire rubber (GTR), thereby providing a potentially new route to recycle discarded tires. The improved dispersion of the blends after mechanochemical milling was confirmed by fluorescence microscopy and polarized optical microscopy (POM) observation. After 20 cycles of milling, the tensile strength of PP/GTR (100/40) blends was enhanced by 13.8%, and the elongation at break was over 12 times than that of the unpretreated blend. The formation of smaller and less ordered spherulites of PP after mechanochemical milling as confirmed by POM observation and wide-angle X-ray diffraction analysis might be the reason for the significant enhancement of the elongation at break.