© 2015 Bentham Science Publishers.Nanoparticles, including gold nanoparticles (AuNP), have been used in imaging in cancer treatment and as therapeutic agents and drug delivery vehicles. Particularly lignans, also called phytoestrogens, have strong effects on the treatment of carcinomas due to their antiestrogenic, antiangiogenic and proapoptotic mechanism. The aim of this study is to investigate the antiproliferative effects of three lignans-AuNP conjugates, pinoresinol (PINO), lariciresinol (LARI) and secoisolariciresinol (SECO), on the MCF-7 cell lines. For this purpose, first, thiolated β -cyclodextrin (β-CD) was synthesized to achieve a surface modification of AuNP, and then the β -CD modified AuNP was characterized using the transmission electron microscopy (TEM), UV-Visible and Nuclear Magnetic Resonance (NMR) spectroscopy. Then, the selected lignans were conjugated to the β-CD-modified AuNP, and the antiproliferative effect of these conjugates was monitored. The results suggest that when compared to their non-conjugated forms, the AuNP-bound lignan conjugates prevented the proliferation of the MCF-7 cells significantly. Therefore, these AuNP-conjugated derivatives can be new candidate agents for breast cancer therapy.