Our study aimed at assessing the effects of 3 Plants Growth Promoting Rhizobacteria (PGPR) either singly or in combination on maize growth under laboratory and greenhouse conditions. Seeds were inoculated with single and combined solution of 10⁸ CFU/ml of Rhizobacteria. Seeds were not inoculated for the control variant. The highest germination percentage was obtained with the combination of Pseudomonas fluorescens and Pseudomonas putida. This combination also recorded the best vigor index, plants circumferences number of leaves and the leaf area. The maximal heights of plants were observed with seeds treated with Azospirillum lipoferum with an increase of 37.32%. The highest rates of underground dry matter were recorded with A. lipoferum, with an increase of more than 56% comparative to control, while the combination P. fluorescens and P. putida increased the aerial dry matter of 59.11%. Finally, the highest value of the aerial biomass was obtained with the plants treated with the combination of P. fluorescens and P. putida and the highest underground biomass was obtained with plants treated only with A. lipoferum. These results s...