Abstract Transparent Eu3+ doped MgAl2O4 and Eu3+/Na+ co-doped MgAl2O4 nanoceramics have been obtained by a low-temperature high-pressure (LTHP) sintering process using crystalline powders prepared by sol–gel method. Structural properties have been studied by X-ray diffraction (XRD) and analyzed by Rietveld method. Luminescent properties of nanoceramics were investigated by excitation and emission spectroscopy at room and liquid nitrogen temperatures and by measuring luminescence decays. Comparison between nanopowders and nanoceramics has shown modification of their structural and spectroscopic characteristics. Differences of luminescence properties were studied and analyzed with Judd–Ofelt theory and also the effect of Na+ co-doping have been discussed.