Abstract: There is a growing technical difficulty to treat infectious diseases due to molecular mechanisms of resistance to antimicrobial drugs, such as biofilm formation. Here we provide evidence of the antimicrobial potential of the hydroethanolic extract of Moringa oleifera leaves, traditionally used to treat disorders like cardiovascular and endocrine diseases, on clinical isolates of Staphylococcus aureus. The extract was chemically characterized using classic techniques and by ultra performance liquid chromatography (UPLC). We carried out minimum inhibitory concentration tests, as well as minimal bactericidal concentration and minimal biofilm eradication concentration tests. Moreover, we tested the anti-inflammatory potential and assessed the toxicity of the extract on buffalo green monkey (BGM) cells. We also investigated the effects of combining the extract to clinically relevant antimicrobial drugs (i.e., synergistic or antagonistic interactions). The extract was active at 8 g/mL and 16 g/mL for planktonic cells and biofilms, respectively. Its anti-inflammatory potential was confirmed, and it lacked cytotoxicity. No significant interference of the extract on antimicrobial drugs was observed. Flavonoids, tannins, proteins, carbohydrates and vitamin C were detected in the extract. Our data open doors for further studies with isolated molecules of the extract in order to conduct in vivo antimicrobial tests.