Technical Abstract: Fusarium species are among the most studied plant pathogenic fungi, with several species causing diseases on corn, wheat, barley, and other food and feed grains. Decreased yield, as well as diminished quality and value of the grain, results in significant worldwide economic losses. Additionally, Fusarium species produce a chemically diverse array of mycotoxins such as diacetoxyscirpenol, deoxynivalenol, nivalenol, T-2 toxin, zearalenone, fumonisins, fusarin C, beauvericin, moniliformin, and fusaproliferin. The dominant Fusarium species associated with feed grain that produce these mycotoxins are reviewed with emphasis on their current taxonomy, phylogenetic relationships, and general biology. Ecological and environmental factors associated with plant-fungal interactions and potential mycotoxin contamination of feed also are discussed with primary emphasis on two main diseases, head blight of small grains and ear rot of corn. The past quarter-century has provided much detail on the morphology, physiology, genetics, and genomics of Fusarium species. Such data are critical for understanding these fungi and for managing their impact on the safety, value, and yield of quality grain.