Abstract Aim of this study was to investigate the growth inhibitory effect of Artemesis annua L. silver nanoparticles (A.annua AgNPS) on human triple negative breast cancer tumor cell line MDA-MB-231. Cells were cultured and treated with A.annua water extract and A.annua AgNPS to determine the half inhibitory concentration (IC50). Oxidative stress was determined using lipid peroxidation (LPO), ROS generation and by determining the levels of antioxidants, superoxide dismutase (SOD) and reduced glutathione (GSH). Further, the mechanism of apoptotic induction was assessed by DNA fragmentation analyses. We observed that A.annua AgNPS significantly caused growth inhibition by increasing levels of LPO and ROS, in a dose dependent manner with reduced level of endogenous antioxidant enzymes. Increased shear in genomic DNA from MDA MB231 cells treated with A.annua AgNPS shows apoptosis to be the cause of cell cell death. We conclude that A.annua AgNPS can be useed as a therapeutic agent against breast cancer.