The vapor pressures of YbCl3, YbBr3, YbI2, LuCl3, LuBr3, and LuI3 were measured by torsion and Knudsen effusion methods. Their temperature dependences may be reported as follows: YbCl3(s): log(p/kPa) (11.30 +/- 0.20) - (14420 +/- 200)/(T/K) from (944 to 1096) K; YbBr3(s): log(p/kPa) = (11.51 +/- 0.20) (14070 +/- 300)/(T/K) from (891 to 1032) K; YbI2(S): log(p/kPa) = (9.37 +/- 0.30) - (13580 +/- 300)/(T/K) from (968 to 1049) K; YbI2(1): log(p/kPa) = (9.04 +/- 0.25) - (13220 +/- 300)/(T/K) from (1068 to 1192) K; LuCl3(s): log(p/kPa) = (11.68 +/- 0.15) - (14940 +/- 150)/(T/K) from (942 to 1075) K; LuBr3(s): 109(p/kPa) = (11.341 +/- 0.20) - (14040 +/- 300)/(T/K) from (903 to 1038) K; LuI3(s): log(p/kPa) = (11.99 +/- 0.40) - (14276 +/- 300)/(T/K) from (862 to 1004) K. Treating the vapor pressures of YbCl3 and LuCl3 by second-and ihird-law, the following standard sublimation enthalpies, Delta(sub)H degrees(298 K) = (288 +/- 6) and (295 +/- 5) kJ center dot mol(-1), respectively, were derived. Comparison of these enthalpies with those of other rare earth trichlorides, recalculated by using a new set of thermodynamic functions, was made. From the YbBr3, LuBr3, and LuI3 vapor pressures, the second-law sublimation enthalpies, extrapolated at 298 K by estimated enthalpic increments, Delta(sub)H degrees(298 K) = (285 +/- 9), (285 +/- 9), and (288 +/- 9) kJ center dot mol(-1), respectively, were evaluated. For YbI2, Delta(sub)H degrees(298 K) = (302 +/- 6) kJ center dot mol(-1) was obtained by use of thermal functions estimated by analogy with the published data on EUI2.