Cobalt ferrite Co1-xPdxFe2O4 where fraction of Co2+ ion was substituted with Pd2 + (x = 0.05, 0.1 and 0.5 moles) was obtained by fast hydrothermal synthesis using Co, Fe, Pd nitrate precursors and studied by X-ray diffraction (XRD), transmission electron microscopy (TEM) and magnetic measurements. The X-ray diffraction confirms the spinel structure for the obtained compound with particle size in range between 5,6 and 17.6 nm calculated from the full-width at half maximum (FWHM) using the Scherrer formula, as in the table 1 below.tablefigureFig. 1. TEM (a) and EDX for Co Fe2-xInxO4 (x=0,1) The EDX spectrum figure 1 (b) highlight presence of Pd in Co1-xPdxFe2O4 sample (x = 0.1). Transmission electron microscopy (TEM) figure 1(a) was used for microstructural study where we observed that the particles are well defined and cubical in shape. The magnetic behavior was examined by means of the conventional AC method [1] at room temperature where we observed that with increasing the amount of substituent (Pd) saturation magnetization (σ) decreases from ~ 52emu / g for x = 0 to ~ 7emu / g for x = 0.5.