Luminescence properties of BaY2O4:Eu3+ are investigated by the site-selective laser-excitation spectroscopy in the temperature region 15-300 K. The phosphors were synthesized by the Pechini-type sol-gel method for different Eu3+-concentrations. Three different crystallographic sites corresponding to two Y3+ sites (Y1 and Y2) and the Ba site for Eu3+ are identified from the excitation spectra due to the F-7(0) -> D-5(0) transition. Crystal-field splittings of the F-7(1) and F-7(2) multiplets lead to classify three different sites for Eu3+ in BaY2O4 lattice. Luminescence decays and spectral features at each site depend strongly on temperature and Eu3+-concentration in BaY2O4:Eu3+. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.104112jes] All rights reserved.