The phase diagrams of molten salts of the rare earth systems SmCl3-ZnCl2 and SmCl3-ZnCl2-MgCl2 have been investigated by DTA. The phase diagram of the binary system SmCl3-ZnCl2 displays a simple eutectic, e(1) = 290 degrees C (7.7 mol% SmCl3). The phase diagram of the ternary SmCl3-ZnCl2-MECl(2) system is also of simple eutectic type, with the ternary eutectic E = 282 degrees C (7.0 mol% SmCl3, 92.5 mol% ZnCl2).