Despite the remarkable number of publications on the interaction of engineered nanoparticles (ENPs) with plants, knowledge of the implications of ENPs in the nutritional value of food crops is still limited. This research was performed to study the quality of rice grains harvested from plants grown in soil treated with cerium oxide nanoparticles (nCeO2). Three rice varieties (high, medium, and low amylose) were cultivated to full maturity in soil amended with nCeO2 at 0 and 500 mg kg(-1) soil. Ce accumulation, nutrient content, antioxidant property, and nutritional quality of the rice grains were evaluated. Results showed that rice grains from nCeO2-treated plants had less Fe, S, prolamin, glutelin, lauric and valeric acids, and starch. Moreover, the nCeO2 reduced in grains all antioxidant values, except flavonoids. Medium- and low-amylose varieties accumulated more Ce in grains than the high-amylose variety, but the grain quality of the medium-amylose variety showed higher sensitivity to the nCeO2 treatment. These results indicate that nCeO2 could compromise the quality of rice. To the authors' knowledge, this is the first report on the effects nCeO2 on rice grain quality.