A study of the identity and prevalence of Fusarium species, isolated from 1448 farm samples of seed of common wheat, 262 of durum wheat, 865 of barley, and 519 of oats produced in Manitoba, was carried on during the six years 1937 to 1942. A total of 16 species, varieties, or forms of Fusarium, representing seven sections of the genus were isolated and identified. Fusarium Poae (Pk.) Wr., F. Equiseti (Cda.) Sacc., and F. Scirpi Lamb & Fautr. var. acuminatum (Ell. & Ev.) Wr. were the predominant species isolated. Fusarium species, one or more, were isolated from approximately 39% of the samples of common wheat, 38% of durum wheat, 55% of barley, and 59% of the samples of oats. The individual species of Fusarium were isolated from less than 1% of the seeds of the four crops, with the exception of F. Poae, which was isolated from 1.79% of the seeds of oats. Fusarium species, one or more, were isolated from approximately 0.66% of the seeds of common wheat, 0.50% of durum wheat, 1.23% of barley, and 2.21% of the seeds of oats.