Belschmiedia miersii (Gay) Kosterm. (Lauraceae) ("Belloto del Norte") is a little-studied tree endemic of the Central Zone of Chile. Hydrodistillation of leaves and stem bark of B. miersii yielded 0.2% essential oil. GC-MS analysis allowed identification of 31 components. The most abundant compounds were three phenylpropanoids: Sarisan (45.8%), eugenol methyl ether (27.7%) and safrole (5.8%). The oil of B. miersii showed high antioxidant content (TEAC: 750.8 ±9.6 μmol/100 g of essential oil). The anti-phytopathogenic activity was evaluated against pathogens of plants: Fungi (Botrytis cinerea, Gibberella fujikitroi and Phytophthora cinnamomi) and bacteria: (Erwinia carotovora, Pseudomonas syringae and Agrobacterium tumefaciens) . The oil showed anti- phytopathogenic activity against all tested bacteria and fungi, especially against A. tumefaciens (IC₅₀= 5 μg / mL) and P. cinnamomi (IC₅₀ = 200 μg /mL). This study demonstrates that the essential oil of B. iniersii has great potential for applications in food and agricultural industries.