Antimony doped cobalt ferrite with general formula CoSbxFe(2-x)O4 (with x=0.0, 0.1, 0.2, 0.3, 0.4, 0.5) have been synthesized by powder metallurgy method. The structural, chemical, microstructural, magnetic and optical properties have been investigated using XRD diffractometer, Fourier Transform Infra-red Spectroscopy, Scanning Electron Microscope (SEM), Vibrating Sample Magnetometer (VSM) and UV-Visible Spectrometer respectively. XRD micrographs of all the samples have been confirmed the formation of spinel structure having major peaks at (220), (311), (400), (422), (511), (440). The increase in lattice parameter is due to the replacement of smaller cation Fe+3 by larger cation Sb+3. FTIR analysis shows major bond (M-O) vibrational bond confirms the spinel structure. When the concentration of antimony is zero then the value of saturation magnetization is 45.5emu/gm. But there is a sharp increase in Ms at x=0.1, this is due to the doping of Sb. The Co+3 and Sb+3 ions prefer to occupy the site B. After that there is decrease in Ms from x=0.2-0.4 this is may be due to the possible concentration of Sb+3 to the site A as compared to octahedral site. The band gap energy decreases as the antimony concentration increases which is associated with the decrease in grain size.