Abstract: By using an LKB 8721-3 vaporization calorimeter, enthalpies of vaporization of o-and m-dichlorobenzenes and enthalpy of sublimation of p-dichlorobenzene at 298.15K were determined as 48.53±0.12, 47.40±0.08 and 65.15±0.20 kJ mol~(-1) respectively. Data of ΔH_v~° and ΔH_s~° for chlorobenzenes reported here and in literature and their normal boiling points, t_b in ℃, can fit following two linear equations: ΔH_v~° (kJ mol~(-1))=17.51+0.17269 t_b; ΔH_s~° (kJ mol~(-1))=26.25+0.22349 t_b. From these equations other unknown values of ΔH_v~°and ΔH_s~°of chlorobenzenes have been estimated.