The magnetic permeability of LaKMnMoO 6 has been investigated using a resonance circuit. The temperature dependence of both permeability and selectivity was plotted in the temperature range 130-300 K approximately. The D.C. resistivity was also investigated and plotted as a function of temperature, the sample shows a semiconducting to metallic transition with decreasing temperature in the vicinity of T C -the Curie temperature -where a peak in the magnetic permeability plot has also occurred. The fairly high values of permeability in the whole temperature range show that LaKMnMoO 6 may be considered as a high-permeability material useful in many electronic applications.