The thermal conductivity of eight halide crystals has been measured over the temperature range 220°K to 390°K. The thermal conductivities of potassium bromide, potassium chloride, and sodium chloride vary inversely with temperature for the lower part of this temperature range, and are nearly independent of temperature for the higher temperatures of the range measured. The thermal conductivities of cesium bromide, cesium iodide, and silver chloride are nearly independent of temperature throughout the entire temperature range. The thermal conductivities of barium fluoride and calcium fluoride vary more rapidly with temperature than anticipated from aT−1relationship; however, the accuracy of the data is not sufficient to establish the exact form of the variation of the thermal conductivity with temperature. The comparative method used for these measurements is described.