We developed the synthesis of a series of furan-fused tetracyclic analogues of the antitumor agent ametantrone. The reactions included nucleophilic substitution of propoxy groups in 4,11-dipropoxyanthra[2,3-b]furan-5,10-diones with ethylenediamines, producing the derivatives of 4,11-diaminoanthra[2,3-b]furan-5,10-dione in good yields. Studies of anti-proliferative activity on a panel of mammalian tumor cell lines demonstrated that anthra[2,3-b]furan-5,10-diones were the most potent derivatives among heteroarene-fused ametantrone analogues with one heteroatom. We identified several compounds that evoked a growth inhibitory effect at submicromolar concentrations. The anthra[2,3-b]furan-5,10-dione 9 with distal methylamino groups was markedly potent against drug-resistant cell lines with P-glycoprotein overexpression or p53 gene deletion. Furthermore, this derivative attenuated in vitro topoisomerase I-mediated DNA uncoiling at low micromolar concentrations. These results demonstrate that anthrafurandiones are a new class of heterocyclic anthraquinone derivatives with the properties potentially valuable for anticancer therapy.