Three catalysts such as Ni, Mo, and Ni-Mo, impregnated over acid halloysite (Ha-A), were synthesized and evaluated in the n-decane hydroconversion reaction. A natural halloysite (Ha) with a nanotubular structure was previously treated with an aqueous solution of sulfuric acid and then used as a support for the preparation of the catalysts by wet impregnation. From the results obtained by catalytic hydroconversion (isomerization and cracking), it can be established that the solid synthesized with the mixed metal content (Ni + Mo) is better than both catalysts with single metal content (Ni or Mo). A good correlation between the catalytic performance and the relationship structure/properties of the materials was observed by characterization techniques. The nanotubular structure of the catalysts was demonstrated by transmission electron microscopy images. An important decrease of the MoO3 reduction temperature (assessed by hydrogen-temperature-programmed reduction, H-2-TPR) was found as a result of nickel addition, suggesting the formation of NiMoO4 species. This result was confirmed by X-ray photoelectron spectroscopy. In addition, H-2-TPR outcomes helped to verify that at lower temperatures, there was a higher catalytic activity. Besides, the Ha-A nanotubes were stable under thermal and reduced conditions used in the catalytic tests. Such stability is important to facilitate the molecular traffic during the reaction. The catalysts reported here showed a remarkable catalytic activity compared with that of a catalyst typically used as a reference (Pt/Al2O3).