In recent years, there has been significant interest in the identification of plant-derived essential oils (EOs) with health-promoting properties and potential as medicinal agents. Salvia officinalis and Cinnamomum zeylanicum EOs have been shown to act as antimicrobial compounds. In this study, the potential anti-inflammatory activity of these EOs was evaluated in in vitro human and mouse models based on monocytic THP-1 cells and RAW264.7 macrophages. Biosafe concentrations were estimated following cell viability studies and then used to assess the activity of the EOs in LPS-induced inflammation, determined by modulation of the expression of pro-inflammatory genes with RT-PCR and the secretion of cytokines with ELISA. Cinnamomum zeylanicum EO emerged as a more potent regulator of the inflammatory immune response, as evidenced by the significant down-regulation of IL-6 and IL-1b expression and the noticeably reduced levels of IL-6, IL-1b and TNFa detected in culture supernatants. These results suggest that Cinnamomum zeylanicum EO holds potential as an anti-inflammatory agent and further studies are underway to investigate its properties and the mechanisms involved in its activity.