The known N-(2-hydroxypropyl)-methacrylamide copolymer (I) which has a p-nitrophenyl peptide side chain is coupled to ethyl aminomalonate (II) in the presence of Et3N in DMF to give the corresponding amide (III). Alkaline hydrolysis of the diethyl malonate ester groups of (III) affords the sodium carboxylate salt (IV). This is then complexed with the platinum species, generated in situ from cisplatin (V) and silver nitrate, to produce the title polymer-linked platinum complex.