The chemical composition of leaves of Costmary, Balsamita major Desf., cultivated in Tuscany was investigated. This aromatic plant is an important natural resource of bioactive products, such as flavonoids, triterpenes and carotenoids, which give it remarkable pharmaceutical properties (hepatoprotective, antifermentative, spasmolytic, carminative and antiviral). The aim of the present study was to confirm and better define, with three different methods, the relations between the antioxidant capacity and antiradical activity of an extract of Balsamita major Desf. demonstrated in preliminary research. Moreover two specific in vitro tests were used to evaluate the antiinflammatory activity of costmary extract on isolated human monocytes. The results show non-toxic antiinflammatory effects on human monocytes of the active compounds in an aqueous costmary extract. The test used to assess the cytotoxicity of the phytocomplex is based on the brine shrimp Artemia salina L. (Artemiidae), an invertebrate living in brackish and marine ecosystems, virtually no mortality was recorded during the experiment, demonstrating that the costmary extract was not cytotoxic at the tested concentrations (100-500 μl/ml). These relationships have not been reported in the literature for costmary, a rare and forgotten plant. The rediscovery and re-evaluation of aqueous costmary extract for food, cosmetic and pharmacological products could be a good starting point to help science in the prevention of serious human pathologies.In conclusion, costmary cultivation should be increased to favour its use in the cosmetics, food and pharmaceutical fields.