The hydrogenation of microcrystalline raw paraffin from the dewaxing of heavy neutral oil over Ni−Mo/Al2O3 and Ni−W/Al2O3 catalysts was studied at the pilot plant scale. The diameter and pore structure of the catalyst showed a noticeable influence on the properties of treated paraffins. The use of catalysts with a particle size of 1.5−2.5 mm allowed us to reduce the severity of the reaction conditions. To obtain treated paraffins with acceptable Saybolt color values, temperatures of >310°C and pressures of >60 kg/cm2 were needed. High temperatures resulted in cracking reactions and high oil content, which can be prevented by high hydrogen pressure. The Ni−W catalyst showed higher activity and selectivity than Ni−Mo catalysts. Saybolt color values of >+30 and oil contents of <0.5 wt % can be obtained with Ni−Mo catalysts at 350 °C and 60 kg/cm2, whereas a temperature of 330 °C and pressure of 60 kg/cm2 are required for equivalent results with Ni−W catalysts.