Electromagnetic fields have many applications in agriculture, but much still remains to be studied to provide scientific evidence of its potential use as an alternative for improvement of food quality from plants whose seed was irradiated, especially in the physical characteristics of the product. In this study we investigated the effects of the electromagnetic fields on the physical quality of maize grain. Twelve treatments were evaluated from a combination of two maize hybrids (San Juan and San Jose) and five times of exposure to electromagnetic field (3, 6, 9, 12 and 15 minutes) plus a control (no electromag-netic treatment) in a design of randomised complete blocks with four replications. Electromagnetic treatment of the hybrid maize seeds (San Juan and San Jose), applied as a pre-sowing treatment, modifies the physical characteristics of maize grains. It was possible to observe that there were significant differences (p≤0.01) between the experimental treatments and between the hybrids in their grain length (LG), grain width (GW) and 1000-grain weight (TGW). The hectolitric weight (HW) of the hybrids was between 69.05 and 68.98 kg hL-1, respectively. These results could have an impact on the process and quality of the tortilla that is consumed by the population; this is a function of time of exposure to electromagnetic treatment.