Polyvinyltoluene (PVT) is an organic polymer which is luminescent when it is irradiated by ionizing radiation. The luminescence yield is proportional to the radiation stopping power and to the absorbed dose. High stopping power radiations, such as ion beams, induce radiation damage in PVT with the production of C H bond break, dehydrogenation and free radical formation, as investigated by the mass quadrupole spectrometry. The damage reduces the luminescence yield significantly. A reduction of about 50% is obtained with 300keV proton and argon ions, having 300keV energy, at a dose of about 10 1 4 and 10 1 3 ions/cm 2 , respectively.