The kinetics of hydrogenation of p-isobutyl acetophenone using a 10% Ni supported on HY zeolite catalyst was studied experimentally in a batch slurry reactor over a temperature range of 373 - 413, K. The effect of H-2 pressure, p-isobutyl acetophenone concentration, catalyst loading and particle size on concentration-time and H-2 consumption profiles was studied. The rate equations, based on reactions of adsorbed H-2 with liquid reactants/intermediate as rate limiting steps a ere found to represent the hydrogenation kinetics, while the formation of p-isobutyl phenyl ethyl methyl ether was represented by a simple first order kinetics. The kinetic parameters were evaluated and the activation energies were found to he 42.76, kJ/mol, 36.53, kJ/mol, 67.80, kJ/mol 52.8, kJ/mol for different steps. For dp > 5 x 10(-4). m. intraparticle diffusion effects were significant, but the external mass transfer (gas-liquid and liquid-solid) was found to be unimportant. Comparision of experimental H-2 consumption-time profiles for different particle sizes with those predicted using the batch reactor model (incorporating intraparticle diffusion effects) showed atl excellent aggrement.