ABSTRACT The compatibilizing effect of polypropylene maleic anhydride (PPMAH) on the mechanical and morphological properties of polypropylene (PP)/ acrylonitrile butadiene rubber (NBR)/palm kernel shell (PKS) composites were studied. PP and NBR are found highly incompatible and can be improved by compatibilizer such as PPMAH. The composites were melt mixed using heated two roll mill at 180 o C and speed of 15 rpm with six different loading (100/0/10, 80/20/10, 70/30/10, 60/40/10, 50/50/10, 40/60/10 phr) with fixed 5 phr PPMAH. Increasing of NBR loading in PP/NBR/PKS composites decreases the tensile strength and Young's modulus but increases the elongation at break. The results showed that higher tensile strength and Young's modulus were obtained for PPMAH compatibilized composites as compared to uncompatibilized composites. Tensile fractured surfaces observed by scanning electron microscopy (SEM) indicates improved adhesion of palm kernel shell with polypropylene / acrylonitrile butadiene rubber matrices in the presence of polypropylene maleic anhydride.