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Beneficial interactions between plants and some bacterial species have been long recognized, as they proved to exert various growth-promoting and health-protective activities on economically relevant crops. In this study, the growth promoting and antifungal activity of six bacterial strains, <i>Paenarthrobacter ureafaciens</i>, <i>Beijerinckia fluminensis</i>, <i>Pseudomonas protegens</i>, <i>Arthrobacter</i> sp., <i>Arthrobacter defluii</i>, and <i>Arthrobacter nicotinovorans</i>, were investigated. The tested strains resulted positive for some plant growth promoting (PGP) traits, such as indole-3-acetic acid (IAA), 1-aminocyclopropane-1-carboxylate-deaminase (ACC-deaminase), siderophore production, and solubilization of phosphates. The effect of the selected bacteria on <i>Arabidopsis thaliana</i> seedlings growth was assessed using different morphological parameters. Bacterial activity against the phytopathogenic fungal species <i>Aspergillus flavus</i>, <i>Fusarium proliferatum</i>, and <i>Fusarium verticillioides</i> was also assessed, since these cause major yield losses in cereal crops and are well-known mycotoxin producers. Strains Pvr_9 (<i>B. fluminensis</i>) and PHA_1 (<i>P. protegens</i>) showed an important growth-promoting effect on <i>A. thaliana</i> coupled with a high antifungal activity on all the three fungal species. The analysis of bacterial broths through ultra performance liquid chromatography–mass spectrometry (UPLC–MS) and liquid chromatography–electrospray ionization–mass spectrometry (LC–ESI–MS/MS) confirmed the presence of potential PGP-compounds, among these are desferrioxamine B, aminochelin, asperchrome B, quinolobactin siderophores, and salicylic acid.