Abstract: The species Cariniana domestica, popularly known in Brazil as jequitibá-roxo, belongs to Lecythidaceae and is very little studied, although it is used in folk Brazilian medicine. In this work, antioxidant potential, total phenolic and flavonoid contents from the leaves of the plant were investigated. Additionally, HPLC/DAD analysis of ethyl acetate fraction revealed five active phenolic compounds (gallic, chlorogenic and caffeic acids, rutin and kaempferol). Antioxidant potential was determined using DPPH assay. Total phenolics were measured using Folin Ciocalteau and total flavonoid, using aluminium chloride. HPLC/DAD analysis was performed using gradient system. The leaves of C. domestica exhibited high antioxidant activity, as well as a large content of phenolic compounds and flavonoids. IC50 obtained with DPPH assay varied from 5.12±0.34 to 14.17±0.32 μg mL-1. Total phenolic varied from 214.32±0.33 to 510±0.21 μg mL-1 and flavonoid content, from 15.26±0.63 to 39.92±0.03 μg mL-1. The species C. domestica exhibited high antioxidant potential, being ethyl acetate the most active fraction. Several bioactive phenolics were identified and quantified in this fraction. All compounds are described for the first time for the genus Cariniana.