Four trans-palladium(II)- and trans-platinum(II)-chlorido complexes, trans-[PdCl2(2-hmpy)(2)] (1), trans-[PtCl2(2-hmpy)(2)] (2), trans-[Pdcl(2)(2-hepy)(2)] (3) and trans-[PtCl2(2-hepy)(2)] (4) (2-hmpy = 2-(hydroxymethyl)pyridine and 2-hepy = 2-(2-hydroxyethyl)pyridine), have been synthesized and characterized by elemental analysis, IR, NMR, and X-ray diffraction. The binding properties of these complexes with fish sperm DNA (FS-DNA) were investigated by UV titration, viscosity, thermal denaturation and electrophoresis measurements. The complexes can bind to FS-DNA and complex 4 exhibits the highest binding constant. Gel electrophoresis assay demonstrates that all the complexes can cleave the pCMV-beta gal plasmid DNA to a different degree. The cytotoxic activities of the complexes were tested against four different cancer cell lines. In general, the platinum(II) complexes are more effective than the isostructural palladium(II) complexes. Complex 4 shows high anticancer activity, compared to transplatin, cisplatin, carboplatin and oxaliplatin. (C) 2012 Elsevier Masson SAS. All rights reserved.