Transparent conducting cadmium stannate thin films were prepared by spray pyrolysis method on Corning substrate at a temperature of 525°C. The prepared films are irradiated using 120MeV swift Ag 9+ ions for the fluence in the range 1×10 12 to 1×10 13 ionscm −2 and the structural, optical and electrical properties were studied. The intensity of the film decreases with increasing ion fluence and amorphization takes place at higher fluence (1×10 13 ionscm −2 ). The transmittance of the films decreases with increasing ion fluence and also the band gap value decreases with increasing ion fluence. The resistivity of the film increased from 2.66×10 −3 Ωcm (pristine) to 5.57×10 −3 Ωcm for the film irradiated with 1×10 13 ionscm −2 . The mobility of the film decreased from 31 to 12cm 2 /Vs for the film irradiated with the fluence of 1×10 13 ionscm −2 .