Sustainable development of nanotechnology requires an understanding of the long term ecotoxicological impact of engineered nanomaterials on the environment. Cerium oxide nanoparticles (CeO₂-NPs) have great potential to accumulate and adversely affect the environment owing to their widespread applications in commercial products. This study documented the chronic phenotypic response of tomato plants to CeO₂-NPs (0.1-10 mg L⁻¹) and determined the effect of CeO₂-NPs on tomato yield. The results indicated that CeO₂-NPs at the concentrations applied in this study had either an inconsequential or a slightly positive effect on plant growth and tomato production. However, elevated cerium content was detected in plant tissues exposed to CeO₂-NPs, suggesting that CeO₂-NPs were taken up by tomato roots and translocated to shoots and edible tissues. In particular, substantially higher Ce concentrations were detected in the fruits exposed to 10 mg L⁻¹ CeO₂-NPs, compared with controls. This study sheds light on the long term impact of CeO₂-NPs on plant health and its implications for our food safety and security.