This article presents preparation of heart-of-peach palm sheath (20-40 wt %) incorporated polypropylene (PP) composites using a single screw extruder. This study is aimed at the waste disposal problem, a societal concern considering that the peach palm cultivation being an important economic activity of some countries, which generate five times more waste than actual heart-of-palm itself. Both the raw materials and their composites were characterized for specific gravity, compressive and impact strengths, softening temperature, and hardness. It was observed that with increasing filler content the compressive and impact strengths of composites continuously decreased, while specific gravity, vicat softening temperature, and hardness showed the opposite trend. However, the optimum mechanical properties were attained for 30 wt % filler, which was the same filler content at which the highest PP crystallinity index was observed. Results also indicate that the lignocellulosic residue induce beta phase on the PP matrix and decrease thermal stability of the composite. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013