Sugar beet is an important commercially cultivated root crop. It yields more than 100 million tons of sugar, predominantly sucrose, annually for global consumption. Cercospora leaf spot (CLS), caused by Cercospora beticola Sacc, is one of the most threatening foliar diseases to sugar beet crops and can significantly reduce sugar yield. The present study aimed to evaluate ten sugar beet cultivars for resistance to Cercospora leaf spot disease during two growing seasons. Additionally, parameters such as disease severity percentage, root diameter (cm), root length (cm), root fresh weight per plant (g), root yield per feddan (ton), and sucrose content were measured. Our findings showed that the sugar beet cultivars Clavious and Bts 8953 were highly resistant, recording the lowest disease severity during the 2021/2022 season (1.33% and 2% respectively) and the 2022/2023 season (2.67% and 4.33% respectively). In contrast, Lily and Oscarpoly were highly susceptible cultivars, recording the highest disease severity during the 2021/2022 season (18.00% and 19.33% respectively) and the 2022/2023 season (17.67% and 19.67% respectively). Other cultivars exhibited moderate resistance. Infection of sugar beet cultivars impacts root diameter (cm), root length (cm), fresh root weight per plant (g), root yield per feddan (t), and sucrose content, with notable differences observed among the cultivars. Consequently, due to the decline in several quality parameters caused by Cercospora leaf spot infection, selecting and cultivating resistant sugar beet cultivars to CLS is one of the most important control strategies that can be relied upon to reduce the losses resulting from this disease.