This study investigates the effects of solid and liquid lubrication on the friction and wear performance of silicon nitride (Si 3 N 4 ) and gray cast iron. The solid lubricant was a thin silver film (∼ 2 μm thick) produced on Si 3 N 4 by ion-beam-assisted deposition. A high-temperature polyol-ester-base synthetic oil served as the liquid lubricant. Friction and wear tests were performed with pin-on-disk and oscillating-slider wear test machines at temperatures up to 300°C. Without the silver films, the friction coefficients of Si 3 N 4 /Si 3 N 4 test pairs were 0.05-0.14, and the average wear rates of Si 3 N 4 pins were ∼ 5 10 - 8 mm 3 N - 1 m - 1 . The friction coefficients of Si 3 N 4 /cast iron test pairs ranged from 0.08 to 0.11, depending on test temperature. The average specific wear rates of cast iron pins were ∼ 3 10 - 7 mm 3 N - 1 m - 1 . However, simultaneous use of the solid-lubricant silver and synthetic oil on the sliding surfaces reduced friction coefficients to 0.02-0.08. Moreover, the wear of Si 3 N 4 pins and silver-coated Si 3 N 4 disks was so low that it was difficult to assess by a surface profilometer. The wear rates of cast iron pins were ∼ 7 10 - 9 mm 3 N - 1 m - 1 up to 250°C, but showed a tendency to increase slightly at higher temperatures. In general, the test results demonstrated that the solid/liquid lubrication of ceramic and/or metallic components is both feasible and effective in controlling friction and wear.