The platinum complex trans-[PtCl2¿E-HN=C(OMe)Me¿2] was compared to cisplatin for cytotoxicity towards tumour cells, and for cellular pharmacological properties in A2780 and cisplatin-resistant A2780/Cp8 ovarian cancer cells. Trans-[PtCl2¿E-HN=C(OMe)Me¿2] was comparably cytotoxic to cisplatin (mean IC50 after 72 h exposure = 6. 1 microM and 7 microM, respectively) and did not show cross-resistance in A2780/Cp8 cells (resistance factor = 0.9). Cellular accumulation measurements after treatment with equimolar drug concentrations showed that trans-[PtCl2¿E-HN=C(OMe)Me¿2] entered both A2780 and A2780/Cp8 cells much more efficiently than cisplatin, whose accumulation was reduced in A2780/Cp8 cells. Unlike cisplatin, trans-[PtCl2¿E-HN=C(OMe)Me¿2] induced rapidly cell death and cell cycle modifications of treated cells, thus indicating substantially different mechanistic properties.