Abstract: The antitumour activity of cis-bis{imidazo(1, 2-α) pyridine} dichloroplatinum(II) (code named AH6) against ovarian cancer cell lines: A2780, A2780cisR and A2780ZD0473R has been determined using MTT reduction assay. The activity of AH6 is compared to that of cisplatin and previously reported cisplanaramineplatinum (II) complexes code named AH3, AH4, AH5, AH7 and AH8. The compound is found to be less active than cisplatin against all the three cell lines. However, the decrease in activity of the compound in going from the parent cell line A2780 to the resistance cell line A2780cisR is found to be less marked as compared to that for cisplatin, indicating that at the level of its activity AH6 has been better able to overcome resistance. The variations in activity of AH6 with those of AH3, AH4, AH5, AH7 and AH8 illustrate structure-activity relationships.