Rice husk was used as filler in the production of rice husk (RH)-polyester composites and was subjected to three types of chemical modification. The chemical reagents employed in this study were glycidyl methacrylate (GMA), maleic anhydride (MAH), and succinic anhydride (SAH). This study revealed that the chemical modification of RH with GMA and MAH resulted in the enhancements of tensile and flexural properties of RH-polyester composites. The reduction in these properties with respect to those modified with SAH were attributed to the absence of C = C unsaturated groups. Water immersion test showed that chemical modification of the RH improved the dimensional stability of the composites. This was shown in the GMA- and MAH-modified RH-polyester composites. The modification increased the hydrophobicity as well as the crosslinking between the RH and matrix in the composites. The lower performance demonstrated by the SAH-modified composites was due to the inability of the SAH to form crosslinking with the matrix. (c) 2005 Wiley Periodicals, Inc.