A 1 : 1 inclusion compound between γ-CD and the tris chelate complex Eu(NTA)3·2H2O [NTA = 1-(2-naphthoyl)-3,3,3-trifluoroacetone)] was prepared and characterized in the solid-state by powder X-ray diffraction, thermogravimetric analysis, FTIR, 13C CP MAS NMR and photoluminescence spectroscopy. Possible host-guest interaction geometries were generated from ab initio calculations. The photoluminescence results reveal the presence of a metal-to-ligand energy transfer that is much more efficient than that previously reported for the analogous β-CD adduct.