The current study presents the synthesis and evaluation of zinc oxide and silver oxide hybrid nanoparticles for their potential apoptotic and anti-cancer activity. Owing to their small particle size, high surface area, and synergistic effects of embedded biomolecules, microwave-assisted synthesised nanoparticle-based drug delivery systems have significant potential in the field of biopharmaceutics and medicine. The higher activity of the hybrid nanoparticles may be attributed to their spherical shape, crystalline nature and lower particle size of 10–100 nm, as shown by different characterization methods as UV, FTIR, Zeta potential, particle size analysis, XRD, SEM, TEM, ICP-OES examination. The cell cycle analysis, cell death, and apoptosis in breast cancer cells (MCF-7) treated with synthesized hybrid NPs were evaluated in this work. Investigation of cell cycle analysis using flow cytometry has been utilized to analyse different phases of cell division and proliferation. The cytotoxic effect of microwave-assisted synthesised hybrid nanoparticles on MCF-7 cell line was studied using MTT assay and found to have significant cytotoxic activity with an IC50 value of 24.31 µg/ml when compared to standard drug Doxorubicin. Moreover, in vivo toxicity performed in Wistar rats reveals safety of developed hybrid nanoparticles. The findings demonstrate the powerful therapeutic efficacy of synthesized hybrid nanoparticles as well as the potential for development of future anticancer medication. © 2022 Elsevier B.V.