The aim of this work is to investigate the tribological behaviors of epoxy (EP)composites under water lubrication conditions at both varying and constant sliding speeds. In particular, the roles of reinforcing fillers, i.e. carbon and glass fibers, solid lubricants and SiO₂ nanoparticles, on the friction and wear properties of EP were investigated. It is demonstrated that both the reinforcing fibers significantly enhance the wear resistance of EP. Under mixed and boundary lubrication conditions, the addition of SiO₂ nanoparticles into EP conventional composite filled with carbon fibers and graphite reduces the friction and wear. It is revealed that the tribological performance of the fiber-reinforced EP composites is mainly attributed to the high abrasion resistance of the fibers and the tribofilm formation.