Reactions of free radicals produced in gamma-irradiated poly(tetrafluoroethylene) (PTFE) were studied by electron spin resonance spectroscopy. beta-Scission reaction of main chain radicals and fluorine abstraction of chain end radicals were detected directly. The decay reactions of the free radicals were examined in connection with molecular motion of the matrix polymer. The rates of those reactions were also discussed in relation to much heterogeneity in structure. Behaviors of free radicals trapped in crosslinked PTFE were compared with those in non-cross-linked PTFE to clarify the effects of molecular motion and structure on the reactions in the solid state.