[en] The scintillation properties of LaCl₃ crystals, doped with Ce³⁺ concentrations of 0.57, 1.0, 2.0, 4.0, and 10%, are studied under x-ray and γ-quanta excitation at various temperatures. Under x-ray excitation, characteristic doublet Ce³⁺ emission is observed with a maximum at 3.7 eV. Also self-trapped exciton (STE) emission is observed with a maximum near 3.1 eV. The contribution of STE luminescence to the total light yield decreases with increasing Ce concentration. For LaCl₃:0.57%Ce³⁺, the contribution is 33%, whereas for LaCl₃:10%Ce³⁺ it is 4%. The total light yield of the Ce³⁺-doped samples ranges from 38 000 photons per megaelectronvolt (ph MeV^-1) of absorbed γ-ray energy to 47 000(ph MeV^-1) for LaCl₃:0.57%Ce³⁺ and LaCl₃:10%Ce³⁺, respectively. A model is proposed to explain the energy transfer from the host lattice to the Ce³⁺ ions. At these Ce concentrations, energy transfer by STE diffusion is held to be dominant