Gaseous thermal conductivities of six fluorinated methyl ethyl ethers, which are potential replacements for traditional blowing agents, have been measured by a transient hot-wire method. Temperature and pressure ranges of the measurements are from 303 K to 343 K and up to 0.4 MPa, respectively. The uncertainty of thermal conductivities obtained is estimated to be within +/-1%. Simple correlation equations were developed to represent the temperature and pressure dependences on the experimental thermal conductivities. Comparisons of the thermal conductivities between the present fluorinated ethers and those of traditional blowing agents CFC 11 (trichlorofluoromethane) and HCFC 141b (1,1-dichloro-1-fluoroethane) are given.