Ferroelectric substances with the ABO3 perovskite structure are widely used as materials in electronic dvices. Among the fields in which electronic devices based on ferroelectric substances are used, devices exposed to high-energy radiation such as in space, nuclearreactors, and military applications are included. Long-term exposure of such electronic devices to radiation is likely to damage the ferroelectric substances owing to the high-energy radiation effects. Therefore, the development of radioactivity resistant ferroelectric substances is essential for use in high radiation environments. In this work, we investigated the gamma-ray(γ-ray) irradiation effects on the electrical properties of the PbTiO3, Pb(Zr0.52Ti0.48)O3, (K0.5Na0.5)(Mn0.005Nb0.995)O3 thin films. The thin films were prepared using a chemical solution deposition method through a spin-coating process, which were subject to γ-ray with various total irradiation doses from 0–3000kGy. The structural properties as well as the ferroelectric and dielectric properties of the prepared films were examined before and after γ irradiation. We found that the remnant polarization (2Pr) value of the films decreased by ~10% after irradiation up to 3000kGy. Inaddition, the dielectric constant of the films decreased. The observed variation of the electrical properties on the total dose might be mainly associated with the mobile defects in Mn-doped KNN thin films such oxygen vacancy and the stored energy gained from gamma-rays.