Six different essential oils and their joint toxic effect with Vitavax-thiram were tested to control Sclerotium root-rot disease of sugar beet (Beta vulgaris L.) caused by Sclerotium rolfsii Sacc. in vitro all the tested oils exhibited  effect on fungal growth of S. rolfsii. Cuminum cyminum oil was the most effective in inhibiting linear growth of S. rolfsii. The joint toxic effect between Vitavax-thiram and oils of Eucalyptus globulus and C. cyminum showed  the highest effect in reducing the growth of S. rolfsii. Under greenhouse conditions, data indicted that oils have significant effect in improving the number of survived seedlings and reduced root-rot. Seed treatment with C. cyminum oil was more effective in controlling damping-off and root-rot diseases of sugar beet and increasing sucrose percentage, total soluble solids percentage (T.S.S%) and purity % of sugar beet plants sown in soil infested with S. rolfsii. Vitavax-thiram mixed with E. globulus or C. cyminum oils as a seed treatment were the most effective in controlling root-rot disease and increasing percentages of T.S.S., sucrose and purity. C. cyminum showed highest values in increasing activities of peroxidase and esterase enzymes. In the field, coating or soaking of sugar beet seeds with C. cyminum, Nigella sativa, Allium sativum and Matricaria chamomilla oils completely controlled root-rot infection, but C. cyminum gave the highest yield/plot in comparison with other oils. Vitavax-thiram combined with E. glubulus and M. chamomilla as a seed coating were completely effective in reducing sugar beet root rot, but E. glubulus and A. sativum as a seed soaking were the best treatments in controlling root rot disease. Analysis by gas chromatography-mass spectrometry (GC-MS) led to identification of 62 organic compounds from C. cyminum oil including hydrocarbons, alcohols, aldehyds and … etc.