AbstractEnvironmentally beneficial composites can be made by replacing synthetic fibers with various types of cellulosic fibers. Fibers from pine wood, coir, sisal, abaca, coir, etc. are all good candidates. The most important factor in finding good fiber reinforcement in the composites is the strength of adhesion between matrix polymer and fiber. Due to the presence of hydroxyl groups and other polar groups in various constituents of abaca, the moisture absorption is high, which leads to poor wettability and weak interfacial bonding between fibers and the more hydrophobic matrices. Therefore, it is necessary to impart a hydrophobic nature to the fibers by suitable chemical treatments in order to develop composites with better mechanical properties. In the present work, the effect of alkali treatment on the moisture absorption tendency of single abaca fiber was investigated. The results shown that the alkali treated fiber absorbs less moisture than the untreated raw fiber.