Metal halide scintillators are described. More particularly, the scintillators include doped (e.g., europium-doped) ternary metal halides, such as those of the formulas A2BX4 and AB2X5, wherein A is an alkali metal, such as Li, Na, K, Rb, Cs or any combination thereof; B is an alkali earth metal, such as Be, Mg, Ca, Sr, Ba or any combination thereof; and X is a halide, such as Cl, Br, I, F or any combination thereof. Radiation detectors comprising the novel metal halide scintillators and other ternary metal halides, such as those of the formulas A2EuX4 and AEu2X5, wherein A is an alkali metal and X is a halide, are also described.