Mesoporous solids of the general formula Al ₁₀₀ P _x V _y -600, wherex, y=0, 5, 10, 20; and 600 corresponds to the final firing temperature (°C), have been prepared and characterized by X-ray diffraction (XRD), surface area and porosity measurements and SEM/EDX analysis. The incorporation of P and/or V into the original Al ₁₀₀ P ₀ V ₀ solid results in increase of the specific surface area (ssa) from 200 to 390 m ² g ^-1 and the pore volume from 0.43 to 1.19 cm ³ g ^-1 . The maximum effect is resulted by P rather than V while a synergistic action of the two is apparent which is maximized at ca. 15% cumulative addition of the two elements. The highest ssa appears in the Al ₁₀₀ P ₁₀ V ₅ solid while the narrowest pore size distribution (p.s.d.), as described by its full width at half maximum (FWHM), appears in Al ₁₀₀ P ₀ V ₅ solid for which FWHM=2.1 nm. The p.s.d. of the solids is approximated by a mixed Gaussian and Lorentzian component which varies in a controllable manner by the P and/or V addition. The XRD results show that Al ₁₀₀ P ₀ V ₀ possesses the γ-Al ₂ O ₃ structure but the samples become gradually amorphous upon addition of P and/or V up to Al ₁₀₀ P ₁₀ V ₁₀ , while in the samples containing 20% P and/or V the crystal phases of AlPO ₄ and V ₂ O ₅ become apparent. SEM shows that the surface of the crystallites becomes more fragmented by the addition of P and/or V up to 10% addition while 20% addition results in a layered appearance of the crystallite external surface. EDX analysis shows that phosphorus is accumulated on the surface to an amount of around 30–40% for low concentration of P and/or V and 10–20% for higher concentrations. For vanadium the emerging picture is less clear, although some accumulation is detected, a fact due to non-homogeneous distribution of V on the external surface of the mesoporous solids.