This paper discusses the effect of Gamma irradiation on the mechanical properties of thermoplastic natural rubber (TPNR) reinforced with hybrid nanofiller, multi-walled carbon nanotubes and nanoclay, (MWCNTs-OMMT). The hybrid nanocomposites samples have been subjected to gamma radiation with doses started from 0 to 200kGy in air at room temperature. SEM micrographs revealed the fillers orientation in the TPNR matrix also promoted strongly to interfacial adhesion between fillers and the matrix which is contributed significantly to the improvement of the mechanical properties at optimum dose also the degradation of samples with high dose. The changes in the mechanical properties of hybrid nanocomposites after irradiation were attributed to the formation of crosslinks via irradiation.