A systematic dielectric study over a frequency range from 100 Hz to 10 MHz was carried out on ethylene propylene diene monomer rubber (EPDM) mixed with zinc chloride and ammonium iodide with increasing quantities up to 16 and 8 phr, respectively. The measurements were carried out at a room temperature of approximate to 25 degrees C. Dielectric data were fitted in the frequency domain by using three Frohlich terms discussing the different relaxation mechanisms in the system. These terms were interpreted according to the crosslinking that is formed by the addition of such materials to EPDM. The thermal aging for such systems was also studied and the data obtained are compared with those done before aging. The mechanical properties as well as the thermal gravimetric measurements were also studied and the data obtained are discussed.