The paper reports the measurements of the thermal conductivity of gaseous difluoromethane (HFC-32) over the temperature range 254.51 K to 341.76 K and the thermal conductivity of gaseous pentafluoroethane (HFC-125) over the temperature range 251.21 K to 333.70 K near the saturation line. The thermal conductivities were measured in a transient hot-wire instrument employing two anodized tantalum wires as the heat source with an uncertainty of 3%. The results were correlated as a function of temperature and compared with the results from the literature.