An eco-friendly and cost-effective technique for the synthesis of R. emodi roots extract (RERE)-mediated bimetallic silver–copper nanoparticles (Ag–Cu NPs) with anticancer and antibacterial applications are reported in the present investigation. Ag–Cu NPs were characterized using different techniques such as UV–visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), field emission scanning electron microscopy and X-ray diffraction (XRD) to reveal physicochemical properties. The XRD analysis illustrates the face-centered cubic crystallinity of Ag–Cu NPs with space group and space group no. 225. FTIR analysis portrays that the phytochemicals present in the RERE play a key role in stabilizing the Ag–Cu NPs. The optical analysis was carried out through UV–Vis spectroscopy. TEM analysis shows that Ag–Cu NPs are spherical in dimension with an average particle size of range between 40 and 50 nm. SAED ring pattern of Ag–Cu NPs reveals the crystalline nature which completely complements the XRD studies. In the present study, anticancer and antibacterial activities were evaluated against breast cancer cell lines (MDA-MB-231) and bacterial strains (Escherichia coli and Staphylococcus aureus).