The photoluminescence (PL) properties of two Dy 3+ doped ternary niobates, LaNbO 4 and CaNb 2O 6 with fergusonite and columbite structures, respectively are investigated and compared. When the emission line corresponding to electric dipole transition of Dy 3+ at 574 nm is monitored, an intense band due to host excitation is observed in both LaNbO 4:Dy 3+ CaNb 2O 6:Dy 3+ systems indicating host-to-activator energy transfer. The presence of a host emission band at 250-300 nm range under 574 nm excitation indicates that the energy transfer is incomplete. The presence of host lattice emission plays an important role in determining the intensity and spectral response of the phosphor compositions. © The Royal Society of Chemistry 2011.