The novel polycrystalline phosphors BaBi2-xEuxB2O7 (Shablinskii et al., 2019) (x = 0, 0.05, 0.10, 0.15, 0.20, 0.30, 0.40) were obtained by crystallization from glass-ceramics. Single-crystal X-ray diffraction experiments were provided for the x = 0.10, 0.20 and 0.40 samples in order to investigate a distribution of the Eu3+ ions over cation sites. It is shown that the Eu3+ ions substitute the Bi3+ ones in the M1 and M2 sites. Luminescent properties of the BaBi2-xEuxB2O7 phosphors were investigated for the first time. The optimal concentration of the Eu3+ ions was revealed for the sample with x = 0.40, after that an immiscibility of the BaBi2-xEuxB2O7 solid solutions occurs, which is of a structure-dependent nature. Increase of the Eu3+ content leads to a gradual change of chromaticity from light red to orange-red/red. It is expected that the BaBi2B2O7:Eu3+ phosphors can be used as red-emitting ones under LED excitation.