Sugar beet in Switzerland is an important crop, with two sugar refineries producing Swiss sugar; until recently, the sugar produced in Switzerland represented >80% of that consumed in the country; however, a decrease in the cultivated surface accompanied by a decrease in sugar yield has led to a production of less than 50% of the Swiss market. This reduction has been strongly associated with the increased prevalence of several diseases: the Syndrome Basses Richesses (SBR), a serious disease associated with two phloem-restricted pathogens; ii) aphid-transmitted virus yellows (VY), which have re-emerged in Europe following the ban on insecticide seed treatments in 2019; and iii) Cercospora Leaf Spot (CLS), a fungal disease caused by Cercospora beticola. CLS has regained importance in recent years, partially due to challenging climatic conditions, but also to the biology of C. beticola and its rapid evolution, with known isolates resistant to the main fungicide classes and isolates that can infect resistant cultivars. Understanding the presence, spread, epidemiology and molecular diversity of the different sugar beet diseases is essential to propose specific control measures.