Abstract γ irradiation effects on the electrical conductivity behaviour of some new synthesized poly (2, 5-arylidenecyclopentanone)(sample 1), poly (2, 6-arylidenecyclohexanone)(sample 2) and a copolymer (sample 3) have been investigated. Thermal studies over the temperature range 300–500 K showed that the conductivity behaviour follows a two-term Arrhenius-type equation. The first term has a small activation energy which predominates at a lower temperature (extrinsic region) and the second term with a higher activation energy predominates at higher temperatures (intrinsic region). Changes in the activation parameters with the change in the γ-ray dose and the nature of the polymers were discussed. The IR absorption spectra showed a decrease in the intensity of the γ-irradiated sample bands. A mechanism based on the formation of trapped free radicals and their recombination has been suggested …