This study compares the mechanical properties of rice husk (RH) and rice husk ash (RHA) filled polypropylene (PP) composites and the effects of ethylene-acrylic-ester-maleic anhydride (E-AE-MA) and PP-g-maleic anhydride (MAPP) as compatibilizer. In this study, PP/RH and PP/RHA composites were blended at the ratios of 85/15 wt% and compatibilizers at four parts per hundred each, via melt extrusion in a twin-screw extruder prior to injection molding. Mechanical tests were tensile, flexural and impact tests. A morphological study was conducted by scanning electron microscope (SEM). Resultsshow that PP/RHA composite exhibited a 4% significant increase in tensile strength compared to PP/RH composite (р < 0.05) while, PP-RH composite increased significantly by 5 and 3% in flexural and impact strength compared to PP-RHA composite (р < 0.05). MAPP increased significantly the flexural strength of PP-RH and PP-RHA composites by 23 and 21% (р < 0.05) compared to E-AE-MA. PP-RHA-MAPP composite increased significantly the impact strength by 18% compared to PP/RHA/E-AE-MA composite (р < 0.05). There was no significant difference in impact strength between PP/RH/MAPP and PP/RH/E-AE-MA composites (р ≥ 0.05). Overall results indicate that RH imparts better reinforcing effect in PP composite than RHA, while MAPP is a better compatibilizer. SEM study indicates that both compatibilizers improved the filler-matrix interfacial adhesion.