The effect of the pore structure on the hydroprocessing of heavy distillate oils derived from low-temperature coal gasification residues was studied using four NiW catalysts with different pore size distributions. The hydroprocessing was co nducted at. a pressure of 17.5 MPa, a temperature range of 370-410 degrees C, and a 0.50 h(-1) space velocity. The degree of hydrodeoxygenation (HDO) in terms of phenolics removal was influenced by the catalyst pore structure, with the most preferable peak pore diameter for HDO ranging between 6.8 and 16 nm. The catalyst with the highest volume of pores in the 3.5-6 nm range showed the lowest HDO activity. The apparent activation energies for the HDO reaction varied between 59 and 87 kJ/mol, whereby the lowest values are obtained for the catalysts with a peak pore diameter of 11 and 16 nm.