The luminescence of Ba2CaUO6, which has the ordered perovskite structure, is reported. Emission and excitation spectra, quantum efficiency, and decay times were measured at 4.2 K. The temperature dependence of the emission spectra and the decay time were investigated. The results show that, in Ba2CaUO6 energy transfer plays an important role, even at 4.2 K. After excitation in the intrinsic uranate centers, the energy migrates through the lattice till it is trapped at uranate centers near defects. These traps get emptied with increasing temperature. This results in a decrease of the luminescence intensity and the decay time. Furthermore, some results are given on the luminescence of Ba2CaUO6:Eu3+.