A series of ∆ 9,11 -estrone derivatives with A-and D-ring modifications has been synthesized and evaluated as antiproliferative agents. The cytotoxicity was assessed in six cell lines (MCF-7, T47-D, LNCaP, HepaRG, Caco-2 and NHDF) by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and a cell cycle distribution analysis was performed by flow cytometry. Some compounds exhibited relevant cytotoxicity, particularly ∆ 9,11 -estrone, which was the most active against HepaRG cells (IC 50 = 6.67 µM). Besides the relevance of the double bond in the C-ring, the presence of a 16E-benzylidene group increased the antiproliferative effect on MCF-7 and T47-D cells. Moreover, the introduction of iodine in positions 2 and 4 of estrone seemed to induce a selective cytotoxicity for HepaRG cells. Flow cytometry experiments evidenced a 34% reduction of HepaRG cell viability after treatment with ∆ 9,11 -estrone and a cell cycle arrest at the G 0 /G 1 phase. Estrogenic activity was also observed for this compound at 0.1 µM in T47-D cells, and molecular docking studies estimated a marked interaction between this compound and the estrogen receptor α.