The friction and wear performance of carbon fiber in the form of bidirectional fabric-reinforced epoxy (C-E) and its hybrid composites filled with lightweight fly ash cenosphere (CSP) was assessed with and without water as lubricant and compared. This is intended at choosing the best composite for pump handling industrial fluids. Wear tests were conducted at various applied normal loads and at a persistent sliding speed/sliding distance. The involved surface attrition processes of the C-E and their hybrid composites under two different sliding situations were compared and conferred, based on scanning electron micrograph (SEM) images of the scuffed surface of the samples. The test results indicated that the addition of CSP filler increased the resistance to wear of C-E and their hybrid composite. However, the friction coefficient (μ) increased with upsurge in normal applied load for all the composites. Further, the wear loss and μ under water-lubricated situation exhibited lower values compared to dry sliding situation for both unfilled and CSP reinforced C-E composites owing to the boundary lubrication and cooling effect. However, amongst the composites tested, 6 wt. % CSP filler into C-E showed the superior resistance to wear in both dry and water-lubricated situations. C-E and its hybrid composites are sorted by plastic deformation, micro-cracking, and fiber breakage underwent in dry and water-lubricated sliding conditions. Such wear mechanisms are considerably subsided under water-lubricated situation. This accounts for the lower μ and better resistance to wear of the CSP filled C-E hybrid composites under water-lubricated condition. © 2018 Elsevier B.V., All rights reserved.