Renewable cellulosic biofibers appear to be a promising substitute to synthetic fibers as reinforcement in different kinds of polymers. The prime objective of this work was to determine water absorption, chemical resistance, and mechanical properties of the green composites reinforced with ecofriendly natural cellulosic Saccharum cilliare fibers. The mechanical and physicochemical properties of the green composites have been investigated as a function of fiber loading for assessing their applicability in different potential applications in everyday life. The green composites thus prepared have been found to show a universal trend of an increase in properties with fiber loading up to 30%, and beyond this the properties decrease. A fiber/matrix interaction between the polymer and reinforcement has been analyzed based on the mechanical and morphological studies. Overall results suggest that the natural cellulosic S. cilliare fibers were capable of serving as a feasible reinforcement for green polymer composites. (c) 2012 Wiley Periodicals, Inc. Adv Polym Techn 32: E427E435, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21290