The effect of silane treatment on the water absorption properties of bamboo matting reinforced epoxy composites were investigated. Experiments using gamma-aminopropyltriethoxy silane, 3-trimethoxysilylpropylmethacrylate, vinyltris(2-methoxyethoxy)silane, bis[3-(triethoxysilyl)propyl]tetrasulfide, 3-aminopropyltrimethoxysilane, and n-octyltrimethoxysilane were carried out to improve the water resistant property of the bamboo fiber composites. Water absorption in the composites was studied by long term immersion and 2 h boiling in distilled water. The pro-cess of absorption of water was found to follow the kinetics and mechanism described by Fick's theory. Alkali treatment results in reduction of water absorption from 41 to 26%. Further reduction is observed with silane treatment. Water absorption varies between 21 and 24%, minimum being for aminopropyltriethoxysilane treated composite. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 1846-1852, 2010