The effects of PbZrO3 filler in polypropylene were studied by isothermal and nonisothermal chemiluminescence and FT-IR spectroscopy after γ(137Cs)-irradiation at 20, 50, 100 and 250kGy relative to neat material. For the two filler concentrations (2 and 5wt%) the improvement in radiation stability can be noticed. The increase in the filler concentration stabilizes polypropylene matrix, whose oxidation rate decreases sharply even at 250kGy. The interaction of polypropylene matrix with filler is discussed based on the adsorption of free radicals on zirconate particles and the electronic coupling of radiolysis intermediates and filler cations.