A coal-derived naphtha was hydrotreated at a range of severities in a bench-scale reactor using a commercial Co-Mo/Al203 catalyst. Total sulphur and nitrogen contents were monitored as were the phenolic components. The phenolics represented most of the oxygen contribution. Very severe operating conditions were required for removal of these heteroatoms. Ihe relative rate of heteroatom removal at 10.45 MPa and space velocity less than 1.25 x 10-3 g feed per gram catalyst second was found to be: