Ce-doped LaCl3/AECl2 (AE = Mg, Ca, Sr) system eutectics were explored. Ce-doped LaCl3/ AECl2 (AE = Mg, Ca, Sr) eutectics were grown using the Bridgman–Stockbarger method in quartz ampoules. In the case of AE = Mg, Ca, eutectics with submicron-diameter phase-separated scintillator fibers (PSSFs) structure were observed. In the case of AE = Sr sample, a solid solution of La0.708Sr0.292Cl2.708 was observed. The plate sample from the grown eutectics has some transparency. The grown eutectic structure showed a mixture of rods and plates shape. This mixed structure was aligned with a length of around 100–400 μm. The Ce:LaCl3/CaCl2 eutectic showed 345 nm emission ascribed to Ce3+ 4f-5d transition under X-ray excitation. The Ce:LaCl3/CaCl2 sample resulted in the highest light output of 9,000 photon/MeV, which is comparable to the previously reported eutectic scintillator Ce:GdAlO3/α-Al2O3, 9500 photon/MeV. Scintillation decay time of the Ce:LaCl3/CaCl2 sample under 662 keV gamma-ray excitation was 26.8 ns (26%) and 282 ns (74%).