Over 400 mycotoxins, mainly from Fusarium, Aspergillus, and Penicillium species, can contaminate grain due to climatic factors and during storage, causing health issues, reducing grain quality, and affecting bioethanol production. The article discusses prevention strategies, including choosing resistant hybrids, proper nutrient supply, crop rotation, and turning infected plant residues into the soil. Chemical protection against insects, which can damage the grain, is also important. Additionally, assessing infection before harvest and reducing moisture content quickly after harvest can help mitigate the effects of mycotoxins in grain.