Photoluminescence spectra of vanadium oxide supported on SiO2, TiO2, Al2O3, K-doped Al2O3, ZnO and MgO were recorded. All the vanadium-containing solids exhibit room-temperature luminescence in the 550-700 nm region upon excitation from 250 to 400 nm. Significant spectral shifts of the emission maximum wavelength ((phos)) depending on the acid/basic nature of the support have been observed. In this way, the higher the isoelectric point (or zero point charge, pzc) of the oxide support, the higher is the (phos) of the supported vanadia catalysts. The linear relationship between these two properties clearly proves that the characteristics of the oxide support has a direct influence on the phosphorescence, and hence on the electronic states, of the vanadyl group. Kinetic analysis of the luminescence decay of supported catalysts has also been determined.