The final disposal of end-of-life tires is a serious global problem, which can lead to socio-environmental problems when they are not properly disposed of. Countries around the world have laws on the environmentally correct final disposal of end-of-life tires and largely are recycled from the use of their calorific power. The production of polymeric blends containing these tires and thermoplastic polymers is a way to add value to the material, but obtaining satisfactory mechanical properties is often seen as a challenge. In the present work, the influence of dynamic vulcanization is analyzed in blends composed of high-density polyethylene (HDPE)/ground tire rubber (GTR) at different concentrations. Seeking to obtain morphologies of more refined phases, the rubber phase was previously devulcanized by the action of microwaves. The results showed that the dynamic vulcanization was not able to significantly influence the mechanical properties of the blends, due to the lack of compatibility between the phases and the degradation of the rubber phase.