The current study was done at Shenno village, Kafr El-Sheikh Governorate, Egypt during 2017/2018 and 2018/2019 seasons. The results showed that the mean numbers of cotton leafworms larvae throughout the growing season 2017/2018 were 22.10, 16.57 and 12.25 larvae/ sample (30 plants) to the three plantations, respectively. In 2018/2019 season, the mean numbers of larvae/sample were 22.45, 16.14 and 11.25 larvae to the three plantations, respectively. Statistical analysis proved significant differences among three plantations in the two seasons In 2017/2018 season, the overall mean of reduction values in the larva numbers were 82.76,82.33,81.50,81.79 and 81.66% for Tac 48% EC, Diracomel 90% SP, Billy 25% WG, Kenzaban 50% EC and Marshal 20% EC, respectively. Also,the root yield of sugar beet were 21.666, 21.690, 21.642, 21.714 and 21.690 ton/faddan for the previous insecticides, respectively, as compared with 11.928 ton/fad., in the untreated plots. Whereas, the sugar yield were 4.008, 3.904, 3.919, 3.936 and 3.997 ton sugar/ faddan to the plots treated with above mentioned insecticides, respectively, as compared with 1.312 tons sugar/faddan in the untreated plots. In 2018/2019 season, the overall mean of reduction values were 87.00, 87.00, 88.00, 88.03 and 87.33% for Tac 48% EC, Diracomel 90% SP, Billy 25% WG, Kenzaban 50% EC   and Marshal 20% EC, respectively. Also, the root yield of sugar beet were 21.547, 21.452, 21.500, 21.404 and 21.428 ton/faddan for the treated plots with the previous insecticides,  respectively, as compared with 5.976 ton/faddan on the untreated plots. Whereas, the sugar yields were 3.878, 3.818, 3.913, 3.833 and 3.878 ton sugar/faddan to the treated plots with the above mentioned insecticides, respectively, as compared with 0.604 tons sugar/faddan in the untreated plots. Statistical analysis indicated significant differences among treated plots with all insecticides and untreated ones in reducing larva numbers, increasing root and sugar yields in the two seasons. Finally, these results indicated that the importance of insecticides in reducing cotton leaf worms larvae, consequently enhancing root and sugar yield of sugar beet crop.