Present paper gives detailed investigation of Sr[(Mg0.32Co0.01) Nb0.67]O3 [SMCN] thin films deposited on ITO coated glass substrate using Pulse laser deposition technique. In order to probe the stability of SMCN under high energy ion irradiation, swift heavy ion (SHI) beam irradiation experiments are performed using 100MeV O7+ ion beams. The effect of irradiation on films, fluence of 1×1012 and 1×1013 ions/cm2, are investigated by X- ray diffraction (XRD), UV-Vis spectroscopy, atomic force microscopy (AFM) and dielectric measurements. It reveals polycrystalline and uniform columnar growth in as- deposited films. Ion irradiation leads to partial amorphization as observed in AFM results. We have also observed drastic reduction in dielectric loss tangent (Tanδ) values. At 1×1013 fluence film shows very low values of tanδ~0.008 at room temperature. The temperature coefficient of dielectric constant (TCK) after irradiation has drastically fallen to 1/2 of its value in unirradiated film. Optimization of critical irradiation parameters may lead to its applicability in devices.