The electrical conductivities of shock heated air and air-plus-teflon mixtures have been measured using a method similar to the conducting gas-magnetic field interaction method described by Lin, Resler, and Kantrowitz. All measurements were made for an initial shock-tube pressure of 1 cm Hg. The air-Teflon mixture contained about 1 mole percent of Teflon. The shock speeds ranged from 2.93 to 5.58 mm/μsec corresponding to temperatures between 3150 to 6500°K and conductivities between 0.24 and 111 mhos/m. The electron densities corresponding to these conductivity values range from less than 1011 electrons/cm3 to about 1015 electrons/cm3. No difference in conductivity between the air and air-Teflon mixtures was observed. Except for two conductivity values measured for very low shock speeds, all the measured values differ by less than a factor of 2 from theoretical values computed for pure air in equilibrium.