Ligand-free, palladium-supported, poly(N-isopropylacrylamide-co-potassium methacrylate) [poly(NIPA-co-PMA)] hydrogel nanocomposite with different comonomer ratios were synthesized. The developed hydrogel-palladium composites were characterized by SEM, TEM, UV-vis DRS and XRD. The catalytic performance of these hydrogel-palladium nanocomposites was examined for Suzuki-Miyaura cross-coupling reaction of aryl halides with arylboronic acids in an aqueous medium. The hydrogel with comonomer ratio of 8.8:1.6 mmol of NIPA:PMA exhibited optimum catalytic activity, which can be effectively reused 5-6 times without loss of catalytic activity. (c) 2008 Elsevier B.V. All rights reserved.