Polyaniline (PAni) was synthesized by a chemical oxidation of aniline, using ammonium per sulphate in 1 MHCl and was investigated for radiation stability. The chloride salt as well as the base form of PAni (in air, water and HCl media) was subjected to gamma radiation using a ⁶⁰Co source. Radiation induced effect on the stability of PAni was evaluated by the data obtained from elemental analysis and Fourier Transform Infrared (FT-IR) spectroscopy. Anion exchange capacities of PAni before and after gamma irradiation were determined by the neutron activation analysis technique from the measured chloride activity. The ion exchange capacity decreased with increase in the absorbed dose. Chloride form of PAni was more stable towards gamma-radiation compared to the base form.