Faba beans (Vicia faba L.) are affected by a large number of pathogens. Studies carried out in western Siberia revealed the influence of the entomopathogenic fungus Metarhizium robertsii on reducing the development and prevalence of a complex of diseases in faba bean in the field. There was a decreasing tendency of the level of phytopathogen infection of seed material and fragments of underground organs during presowing treatment of the bean seeds with M. robertsii. Treatment with M. robertsii significantly reduced the development of root rot by 2.9 and 9.5 times in 2019 and 2020, respectively, and the prevalence of the disease decreased by 2.9-3.0 times. It also resulted in reduction of the severity of diseases of aerial organs during the growing season on average for the plant: the Disease Development Index (DDI) of powdery mildew by 3.8 times and chocolate spot by 3.5 times. There was a significant increase in the number of active nodules on the roots of plants during the treatment with M. robertsii. The results obtained indicate that the treatment of bean seeds with the entomopathogenic fungus M. robertsii improved the phytosanitary situation of the sowing of the crop, and in the future, this technique can be used in agricultural practice.