Diagnosis of early stage angiogenic tumours is fundamental for cancer therapy. In this study we present the synthesis and characterisation of functionalised HPMA-copolymers with optimal molecular weights that meet the demands of the enhanced permeability and retention (EPR) effect. Rhenium tricarbonyl complexes of the tripodal ligands bis(2-pyridylmethyl)benzylamine (1a) and bis (2-pyridylmethyl) -4-vinylbenzylamine (1b) were prepared and characterised by H-1 NMR and IR spectroscopy, mass spectrometry and X-ray diffraction. Ligand 1b was copolymerised with N-(2-hydroxypropyl)methacrylamide (HPMA), and the resulting copolymer was treated with (nBu(4)N)(2)Re(CO)(3)Br-3] to yield a Re(CO)(3)-labelled copolymer. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim., Germany, 2007).