The common sage (Salvia officinalis L.) is one the most popular medicinal and aromatic plant species belonging Lamaiceae, native to the Mediterranean region, although it has been naturalized in many places throughout the world mainly because of to its high medicinal value. A greenhouse experiment was carried out to determine the antioxidant activty of S. officinalis L. plants inoculated with four rhizobacteria strains namely Pseudomonas fluorescens (Pf Ap1, Pf Ap18) and P. putida (Pp Ap9, Pp Ap14). rhizobacteria suspensions were diluted in sterile distilled water to achieve the final concentration of 108 CFU ml-1. The suspensions were subsequently applied to the soil, cuttings and leaves.Totally, 60 ml of the final suspension was applied for each treatment The control cuttings received the same amount of distilled water. The experiment was arranged based on completely randomized design and replicated at three times. Plants were harvested after four months at the full flowering stage. The air-dried and finely powdered shoot tissues were Soxhlet-extracted using the method of Sokmen et al.,[1]. The antioxidant activity of the plant extracts was studied using free radical 2, 2- diphenyl-1- picrylhydrazyl (DPPHo)and ß-carotene/linoleic acid assays basedon Burits and Bucar method [2]. Here, lower value of IC50 indicate higher antioxidant activity, therefore, PGPR inoculation significantly (p < 0.05) enhanced the antioxidant activity compared to the uninoculated control. According to the results, the extract from plants inoculated with the Pf AP18 strain was the most active one with an IC50 value of 15.7 μg mL-1 as compared to that of control plants (26.7 μg ml-1) and BHT as positive probe (20.4 μg ml-1). For the ß-carotene/linoleic acid bleaching methods, however, the improved antioxidant activity was only observed in plants inoculated with Pf Ap1, Pf Ap18 and Pp Ap14. In conclusion, the beneficial rhizobacteria are promising biological components with the capacity to e
