Ceramic substrates (alumina and zirconia) coated with silver by an ion-beam-assisted deposition (IBAD) process were subjected to laboratory wear tests at temperatures up to 400°C. Tribological data indicate that the friction coefficient of these coated ceramic substrates was reduced by a factor 2 to 3 below that of uncoated substrates. Wear was also reduced by as much as three orders of magnitude, depending on the type of ceramic, sliding velocity, and temperature. These effects were attributed to the improved adhesion, provided by the IBAD process, of the lubricious Ag coatings to the alumina. To verify this, adhesive strength of the Ag coatings was measured with a thin-film adhesion pull tester. The results of these tests indicated that the IBAD Ag films had an order-of-magnitude higher adhesive strength than Ag films deposited by conventional physical-vapor-deposition processes. Results of these tests and the effects of IBAD processing parameters on the adhesion of Ag coatings to ceramics are presented.