Abstract: Background and Objective: The surface physicochemical characteristics play a crucial role in adhesion and biofilm formation. Adhesion process is central to many environmental, industrial and medical applications. Medicinal plants extracts are commonly used in these applications and can potentially influence the bacterium/surface interaction. Two bacterial strains, Staphylococcus aureus CIP54354 and Bacillus subtilis ILP142B and two medicinal plants aqueous extracts types Salvia officinalis and Myrtus communis were examined upon bacterial cell surface physicochemical properties. Methodology: The effect of medicinal plants extracts on bacterial cell surface physicochemical properties was examined using a combination of contact angle measurements, Lifshitz-Van Der Waals (LW) and acid-base (AB) surface free energies calculations. Results: The study demonstrated that plants aqueous extracts treatment could modify cell surface tension parameters including Lifshitz-Van Der Waals (γLW), electron-donor (γ–) and electron-acceptor (γ+) and thereby the bacterial cell hydrophobicity, depending on the aqueous extracts type and concentration and the bacterial surface characteristics. Conclusion: A possible application of these findings in the pharmaceutical industry for the production of compounds supporting antibiotics for treating oral diseases seems to be worth exploring.