Eyespot belongs to most destructive of foot rot diseases of cereals, because it occurs on the best soils and owing to a great number of host plants. To assure a satisfactory chemical protection of cereals against Pseudocercosporella herpoirichoides (Fron) Delghton the knowledge of the etiology of this disease and the biology of the pathogenic agent is needed. Till now the benzimidazole fungicides are used on a large scale. Since 1982 in West Europe the resistance of the fungus - P.herpotrichoides to benzimidazole fungicides has been observed. Thus the necessity of exact investigation of this problem in agroecological conditions of Poland is important.