The thermal conductivity has been measured for the phases; liquid, Ib, II, III and IV of CCl4using the transient hot-wire method. Measurements were made at pressures up to 2·2 GPa, and in the temperature range 166–413 K. The thermal conductivity of the plastic crystal phase Ib was found to have features which are closely similar to those found for the plastic crystal phases of cyclopentane and cyclohexane. Phase IV of CCl4was found to form at pressures in the region of 1 GPa—substantially lower than reported in previous work.