A macroporous cross-linked acrolein-styrene copolymer was synthesized and the aldehyde groups were converted to hydrazone (P-HZ) or phenylhydrazone (P-PHZ) derivatives. Studies of the basic characteristics of the two resins showed that they are highly selective for gold and platinum in aqueous acidic solution. Distribution coefficients, as a function of acidity, were determined for fourteen metal ions. The noble metal ions Au(III). Pd(II) and Pt(IV) could be separated from base metal ions or concentrated from very dilute solutions on short resin columns.