Heat capacities of solid SmCl 3 and TmCl 3 were measured by differential scanning calorimetry in the temperature range from 300 K up to the respective melting temperatures. The heat capacity of liquid SmCl 3 was also investigated. These results were compared with literature data and fitted by a polynomial temperature dependence. The temperature coefficients were given. Additionally, the enthalpy of fusion of SmCl 3 was measured.