A new bio-polymer heterobimetallic complex wool-Pd-Co is found to be a novel efficient catalyst for asymmetric hydration of unsaturated carboxylic acids with high enantioselectivity by simple and clean process under mild conditions. Chemical and optical yields are affected by some parameters, such as the (Pd + Co) content in wool-Pd-Co, the Co/Pd molar ratio, reaction time, reaction temperature and amount of water. After five-time use of the complex, the chemical and optical yields of the products show no significant changes. Obviously, the methods provide an alternative way to produce chiral beta-hydroxycarboxylic acids. (c) 2006 Elsevier B.V. All rights reserved.