AbstractThe luminescence properties of some silica‐supported transition‐metal (Mo, W, Nb, Re) oxide catalysts are reported under dehydrated conditions and at low temperatures. The luminescence results are used to identify the metal oxide species in the catalyst samples. UV/VIS reflection spectroscopy is used as an additional tool. The anomalously long decay times of the luminescence of the Mo/SiO2, W/SiO2 and Nb/SiO2 samples indicate that in these samples there are strongly distorted monomeric oxo‐transition‐metal species present. The luminescence of the Re/SiO2 sample is very weak. It is the first report of luminescence of a perrhenate complex. Finally, the possibilities to use luminescence spectroscopy to characterize supported transition‐metal oxide catalysts are evaluated.