In this study, oil palm empty fruit bunch (EFB) pulp Was used as reinforcing agent in polypropylene composite. EFB pulp was prepared using soda pulping with different concentrations of sodium hydroxide (NaOH) solution. Overall, the tensile and flexural properties specifically the strength and the toughness showed improvement as the NaOH content in the treatment was increased. This was attributed to lower probability for EFB Pulp to agglomerate and the production Of higher aspect ratio pulp fibers. Scanning electron microscopy analysis showed evidence of the reduction ill EFB bundles diameter after NaOH treatment. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 116: 1867-1872, 2010