AbstractDiamond and diamondlike carbon films possess several unique characteristics that govern their tribological properties, in particular their high hardness and lubricity nature. In this paper, the influence of the deposition methods on the adhesion of the films and on their wear resistance and frictional properties is summarised. It is observed that the deposition technique contributes greatly to the variation in microstructure of the diamond or diamondlike carbon film. The multitude of tribotesters (pin-on-disc, reciprocating ball-on-plate, ball-on-three flat, etc.) used to evaluate these films also complicate the interpretation of the tribological performance and confuse direct comparisons of the deposition techniques. Also, the effect of non-diamond carbons and hydrogen in the film is elucidated in relation to the friction coefficient. The application of these films to rolling and sliding components in various industries is highlighted, together with their limitations. The hard brittle nature of the film makes it an excellent candidate in abrasive and erosive applications, but less desirable in rolling contact. Choice of substrate material is critical in order to support the film under high contact stresses.MST/1692