A series of Europium-substituted cobalt ferrites (CoEuxFe2-xO4  with = 0.00, 0.10, 0.20, 0.30)  were synthesized by hydrothermal method. The structural characterizations of all the prepared samples were done using XRD and FTIR. These studies confirmed the formation of single-phase spinel structure in all the compositions. The increase in the value of lattice parameter with increase in Europium concentration suggests the expansion of unit cell. The Hall-Williamson analysis is used for estimating the average crystallite size and lattice strain induced due to the substitution of Europium in the prepared samples. Crystallinity and the crystallite size are observed to increase with the concentration of Europium. The surface morphology and particle size of a typical sample were determined using SEM and TEM respectively. The substitution of Europium strongly influences the magnetic characteristics, and this is confirmed from the magnetization measurements at room temperature.