Four mononuclear trans-planaramineplatinum complexes code named JH1, JH2, JH3, and JH4, and two trinuclear complexes code named JH5 and JH6 have been prepared and characterised based on elemental analyses, IR, mass and 1H NMR spectral measurements. The activity of the compounds against human ovarian cancer cell lines A2780, A2780cisR and A2780ZD0473R, cell uptake, level of binding with DNA and nature of interaction with pBR322 plasmid DNA and salmon sperm DNA have been determined. Among the mononuclear complexes JH1 is found to be most active: four times more active than cisplatin in the resistant cell line A2780cisR and six times more active in the resistant cell line A2780ZD0473R. Between the two trinuclear compounds, JH6 is found to be more active than JH5 in all three ovarian cancer cell lines A2780, A2780cisR and A2780ZD0473R. JH6 is also more active than cisplatin in all the ovarian cell lines A2780, A2780cisR and A2780ZD0473R: two times more active than cisplatin in the parent cell line A2780, three times more active in the resistant cell line A2780cisR and about two times more active in the resistant cell line A2780ZD0473R.