The effect of the mechanical mixing for Pd/H-ZSM-5 and Pd/gamma-Al2O3 catalysts over different concentrations (0, 25, 50, 75 and 100 wt. % as base Pd/H-ZSM-5 catalyst) was investigated in the hydrotreating of castor oil at different reaction temperatures (340, 360 and 380 degrees C). The presence of H-ZSM-5 increased the specific area of the final catalyst. Consequently, a higher Pd dispersion was observed. The above allowed a higher transformation of the castor oil into gas and atmpospheric distillates (< 360 degrees C) since thermal and catalytic cracking reactions were promoted. Pd/75Z catalyst (75 wt. % of Pd/H-ZSM-5 catalyst) presented the best behavior during the hydrotreating of castor oil.