Extension of the newly reclaimed areas for agriculture in Egypt has obviously affected the microclimate of the insect pests, which seriously threatens the cultivated field crops. Besides, the role of the major natural enemies must be carefully understood. Therefore, a field study was conducted in El-Farafra Oasis, Western Desert, Egypt to assess biodiversity and population dynamics of major natural enemies found associated with three field crops (faba bean, cotton, and alfalfa) by sweep-net and beat and shake sampling. The species diversity of natural enemies included 27 species, 23 genera, 14 families belonging to six orders and the total abundance of these species was 5098 individuals sampled during 2018 and 2019. The most common insect order was Coleoptera (composing 42.2% of the total abundance) followed by Hymenoptera (28.1%) and Neuroptera (17.8%), whereas the smallest number of individuals found in Odonata (2.1%). Similar population dynamics of natural enemies in the three crop fields were observed during the two seasons, and most species showed a positive correlation with temperature and negative correlation with relative humidity. The values of species diversity, richness, and evenness indices were higher in the alfalfa field (2.529, 2.623, and 0.846, respectively).