The vacuum thermal conductivity of lunar fines sample 14163 was measured for the approximate temperature range of 100¿--400¿K. Several sample densities from 1100 to 1800 kg/m3 were used. The temperature dependence of the conductivity was found to be well represented by the relation &kgr;=A+BT3, which is predicted by elementary theory. The coefficients A and B were obtained by least squares analysis of the data. The thermal diffusivity was calculated for the various densities by using specific heat data from the literature along with the measured conductivities. The results are compared with those obtained for Apollo 11, Apollo 12, and terrestrial basalt samples.