This paper reports on the synthesis and characterization of Lasub.2Osub.3:Eusup.3+ luminescent aerogels fabricated by the sol–gel method and the supercritical drying technique. The % mol concentration of the Eusup.3+ ion was varied to study the effects on the luminescent properties of the aerogels. XRD and TEM analysis showed that the Lasub.2Osub.3:Eusup.3+ aerogels exhibited a semi-crystalline behavior regardless of whether the concentration of europium was increased. SEM micrographs revealed a porous structure in the aerogels, which were composed of quasi-spherical nanoparticles that were interconnected and formed coral-shaped agglomerates. Photoluminescence spectroscopy characterization showed that the aerogels had an infrared emission located at λ = 793 nm, and the maximum photoluminescence emission intensity was observed for the aerogel with 50% Eusup.3+. The results demonstrate that, without heat treatment, it is possible to manufacture luminescent aerogels of rare-earth oxides that can be used in opto-electronic devices.