This article presents, the systematic and successful preparation of cadmium substituted cobalt ferrite (Co1-xCdxFe2O4) nanoparticles via simple co-precipitation method. X-ray diffraction study confirmed the prepared ferrite nanoparticles were crystallized with a mono phase cubic spinel structure of Fd3m space group. The average crystallite size (Dxrd) was increased with Cd doping content, due to the replacement of Co2+ ions by Cd2+ ions. XRD pattern revealed the high intense peak corresponds to (311) lattice plane and confirmed the formation of cubic structure ferrite nanoparticles. Morphological study was done by using SEM images. The grain size found to be increased with Cd concentration and it reaches the highest of around 0.9μm for Co0.52Cd0.48Fe2O4 composition. Fourier Transform Infrared spectroscopy of prepared samples was recorded in the range of 1000-350 cm-1, confirmed the spinel structure.