Sulfur was added to hydrous zirconia using a number of methods. Sulfur was added using ammonium sulfate, H2S, SO2 as well as H2SO4, The impact of the method of sulfur addition on the properties of the catalysts is reported. The activity was evaluated for all catalysts prepared by measuring the conversion of n-hexadecane in batch reactors. The H2SO4, ammonium sulfate and SO2 methods of sulfur addition produced the most active catalysts, These catalysts were then studied in a trickle bed reactor. The hydrocracking and hydroisomerization yields were independent of the method of sulfur addition and strictly a function of conversion. One of the methods using SO2 produced a catalyst which showed high activity for over 500 h on stream.