The current study investigated the role of inoculating groundnut with isolated Rhizobium leguminosarum under water stress.  Three levels of irrigation {80% (control), 60% (D1), and 40% (D2) of field capacity} were employed in the presence or absence of Rhizobium. Results revealed that plant growth biomarkers and physiological attributes were altered under drought conditions, while Rhizobium-groundnut-symbiosis with or without water stress showed a remarkable improvement in plant growth (branch number, shoot and root fresh and dry weights) photosyntheticpigments and the quantum yield of PSII (Fv/Fm) as well as the increase in nodules' weight, number, leghaemoglobin, and N₂ contents. The electrograms displayed quantitative and qualitative characteristic changes among the D1 and D2 separately or with Rhizobium inoculation. Drought-induced synthesis of high or low MWs new stress protein bands with low intensities; additionally, Rhizobium inoculation resulted in the increase in the number of bands, besides the elucidation of the relationships among different treatments as showed by dendrogram cluster analysis. The overall results suggest that Rhizobium-symbiosis regarded as a promising and effective tool for the modulation of groundnut to conquer water deficiency.