Colombian montmorillonite (bentonite) and saponite have been pillared with oxo-hidroxyaluminium solutions, and activated acid with clorhidric acid of different concentrations. The solids have been examined by X-ray diffraction. The textural properties, residual cation exchange capacities, and acid contents have been established. The pillared clays exhibit stable thermally spacings, specific surface areas, and micropore typical of such materials. The catalytic properties have been evaluated over Pt impregnated samples in the heptane hydroconversion reaction. Al-pillared saponite show superior catalytic performance. The higher activity is attributed to the higher content and strength of the acid sites associated with Si-OH-AI groups produced upon proton attack of the tetrahedral Si-O-AI bonds. Such strong acid sites are absent in Al-pillared montmorillonites.