The production of different size and shape silver nanoparticles (AgNPs) has increased considerably in recent years due to several commercial and biological applications. Here, rod-shaped AgNPs (SNRs) were prepared using the microwaveassisted method and characterised by ultraviolet-visible spectroscopy, and transmission electron microscopy analysis. The present study aims to investigate the cyto-genotoxic effect of various concentrations (5, 10, and 15 μM) of SNRs using Allium cepa model. As a result, concentration-dependent cyto-genotoxic effect of SNRs was observed through a decrease in the mitotic index, and an increase in the chromosomal aberrations such as chromosome break, disturbed metaphase, and anaphase bridge. To check the impact of Ag+ ions, 15 μM silver nitrate (AgNO3) was prepared and tested in all the assays. Furthermore, cell viability and different reactive oxygen species assays were performed to test the cytotoxicity evaluation of SNRs. The authors found that in all the tested assays, SNRs at high concentrations (15 μM) and AgNO3 (15 μM) were observed to cause maximal damage to the roots. Therefore, the current study implies that the cytotoxicity and genotoxicity of SNRs were dependent on the concentration of SNRs. © 2019 The Institution of Engineering and Technology.