Introduction: Ugni molinae Turcz., Ugni candollei Barn. (Berg) and Ugni selkirkii (Hook. et Arn.) Berg are Chilean species that share morphological characteristics and they are distributed in geographic locations with very diverse habitats. Its is considered important for the characterization of the Chilean flora to determine if there are similarities in the sort of chemical compounds among species with close morphological relations, growing in different habitats and their consequent biological activity. Objective: to assess the chemical composition and the antioxidant capacity of leaf extracts from the Chilean species of the genus Ugni, and to compare with the U. molinae characteristics. Methods: composition of chemical compounds was determined by chromatographic methods (HPLC-ESI-MS). The antioxidant capacity was assessed by DPPH, ABTS and by stabilization of the hydroxyl radical. Results: as expected, given the great morphological similarity existing among the three species of Ugni that grow in Chile, similarities were found in their chemical composition. Nevertheless, it was also expectable to find variations among them. Thus, U. candollei and U. selkirkii are the species that present greater content and variety of phenolic and terpenic compounds. These species exert greater antioxidant capacity in comparison to U. molinae. U. candollei hightlights for its flavonoid content such as glycosides and quercetin derivatives, and the species U. selkirkii, is important in galotannins. U. molinae is characterized in ellagic acids derivatives. Conclusion: these data and the morphological characteristics could become a useful toll in order to determine the closeness degree among these species.