Monitoring resistance in the whitefly Bemisia tabaci (Genn) in the three Egyptian Governorates, Beni-suif, Giza and Sharkia using three insecticides from the neonicotinoid compounds confidor (imidacloprid), actara (thiamethoxam) and chess (pymetrozin) were studied. To obtained results clearly indicated a great effect of these neonicotinoid with LC₅₀ʹs 0.02, 0.05 and 0.13 ppm forconfidor, actara and chess, respectively, against laboratory strain. The insecticide confidor was most potent one among the three tested insecticides with less LC₅₀ʹs 0.03, 0.35 and 0.49 for Beni-suif, Giza and Sharkia respectively. Beni-suif field population was the most susceptible one compared with the other populations, where LC₅₀ values were 0.12, 0.03 and 0.25 ppm for actara, confidor and chess, respectively. Thus, the collected adults in different populations  which treated with insecticides under this study compared with   laboratory strain. Sharkia Governorate population displayed the highest resistant ratios at LC₅₀ and LC₉₀ levels were,14.8 and 13.8 fold for actara, 24.5 and 19.3 fold for confidor and 28.6&17.9 fold for chess insecticide, respectively. Also, quantifying the activity of the detoxification enzymes (MFOs, GST and α-esterases) were assessed, it was found that a correlation between the increasing in resistance and the activity of these enzymes. Beni-suif Governorate population which was susceptible one among all tested populations, it showed less levels in detoxifying enzymes activity, with values 32.2, 6.13 and 27.63 for α-esterase, GST and MFOs respectively.