In this study, Y3-xCdxFe5O12 (0.0 ≤ × ≤0.2) powders were synthesized via the co-precipitation method at calcination temperature 1100 °C. The phase formation of YIG was confirmed from X-ray powder diffraction (XRD) and Fourier Transform Infrared (FTIR) technique. The change of the band-gap energy, determined from the analysis of UV-visible spectroscopy, with the particle size was in agreement with the quantum confinement effect for x between 0.02 and 0.2. The magnetization study showed a non-monotonic change in the saturation magnetization and the coercivity with the increase of Cd2+ content. This behavior is an indication of both effect of particle size and the concentration of the doped Cadmium. The Mӧssbauer spectroscopy analysis confirmed the existence of Fe3+ in both octahedral and tetrahedral sites and the non-existence of Fe2+.