Carbon nanotube-metal-oxide composites (metal=Fe, Co or Fe/Co alloy; oxide=Al 2 O 3 , MgO or MgAl 2 O 4) have been prepared by hot-pressing the corresponding composite powders, in which the carbon nanotubes, mostly single or double-walled, are very homogeneously dispersed between the metal-oxide grains. For the sake of comparison, ceramic and metal-oxide nanocomposites have also been prepared. The microstructure of the specimens has been studied and discussed in relation to the nature of the matrix, the electrical conductivity, the fracture strength and the fracture toughness. The carbon nanotube-metal-oxide composites are electrical conductors owing to the percolation of the carbon nanotubes.