A chemical devulcanization process of waste tires was investigated using different peroxide derivatives as devulcanizing agents. This radical process afforded the recovery of functionalized elastomers with a well-defined architecture, in up to 60% yields, directly from ground tire waste and simultaneously afforded the functionalization of the residual vulcanized waste. Kinetic studies provided a better insight into the radical reaction behavior in such complex materials. This mild process constituted a facile route to recover the elastomers contained in waste tires and more generally in sulfur-cross-linked rubbers.