<p>Results are given for a comparison of the textural and catalytic properties of mixed nickel-aluminum oxides depending on the ratio of the metal ions in solution used in the synthesis of their precursors. The structure of these mixed oxides was studied by x-ray structural analysis and nitrogen adsorption-desorption. The ratio of the nickel and aluminum ions in these mixed oxides was found to affect their catalytic properties in the cracking of linear alkanes and heavy oil. When the Ni²⁺/Al³⁺ ratio was 2:1, the mixed oxide was found to have the most well developed surface and greatest catalytic activity in the cracking of n-alkanes and heavy oil components. Nickel-aluminum oxides have catalytic activity in the isomerization of alkanes, which suggests their use as supports for hydroisodewaxing of the middle distillate of hydrocarbon fractions.</p>