PLANT growth-promoting endophytic bacteria (PGPEB) are beneficial microbes that can be applied to improve plant responses to drought stress. In this study, seven bacterial isolates were purified from the root-endosphere of field-grown wheat (Triticum aestivum L.) in Egypt. Bacterial isolates were identified and in-vitro screened for plant growth-promoting (PGP) traits and water deficit stress alleviation. Then, the effect of bacterial inoculation on growth promotion and performance of wheat was investigated under full irrigation and water deficit stress in greenhouse and field experiments. Based on 16S rRNA gene sequences, three isolates were classified as Bacillus sp., whereas, four isolates were identified as Enterobacter, Paenibacillus, Pseudomonas, and Sphingomonas sp. All isolates produced indole acetic acid, solubilized inorganic phosphate, secreted siderophore, and exhibited tolerance to osmotic stress. Under greenhouse conditions, growth, shoot-N content and leaf proline content of wheat plants inoculated with most bacterial isolates were significantly (P< 0.05) increased under both normal irrigation and water deficit stress (50% water holding capacity). Based on greenhouse results, Bacillus sp. strain NGB-WhE3 was evaluated to alleviate water deficit stress on five wheat cultivars (Giza 171, Misr 1, Misr 3, Shandaweel 1, and Sids 14) in two-year field trials. Bacterial inoculation significantly (P< 0.05) improved the agronomic traits and some physiological characteristics of wheat plants under water deficit stress than the uninoculated control. Grain yield of inoculated wheat plants showed significant (P< 0.05) increases from 5.6 to 14.6% under normal irrigation and from 3.2 to 12.5% under water deficit stress.