Bacterial resistance to antibiotics is now a major public health problem in the world as well as in Morocco. The situation appears particularly worrying in hospital since it disseminates the micro-organisms to long distance, and insidiously contributes to their transmission to various inert media. Infections favored may be reduced by the mastery of the environment and the establishment of good disinfection strategy, based on natural and powerful molecules. In this context, we have tested the antibacterial action of two essential oils (Thymus vulgaris and Lavandula officinalis) on 27 strains collected from the environment of the Al Ghassani hospital's hemodialysis center of Fez city. The determination of the antibacterial power was conducted by the Vincent method. The minimum inhibitory concentrations (MIC) of the various essential oil were determined by the solid medium diffusion method. The oil of Thymus vulgaris showed a strong antimicrobial activity against the strains studied with diameters of inhibitions between 16 to 40 mm. The HE Lavandula officinalis presented narrow antibacterial activities, with diameters of inhibition ranging from 8 to 28 mm. The MIC of lavender are more important than those of thyme. This activity could be due to a synergy of their major compounds. It would be interesting to analyze the chemical composition of these oils, to maximize the impact of the factors that can amplify their efficacy, and to establish disinfection