In this study was evaluated the antioxidant activity of plant Palicourea guianensis (Rubiaceae), for which extraction was done by the aerial part of the species with methanol as the primary solvent, after this, the crude extract was fractionated with the following solvents: n-hexane, dichloromethane, ethyl acetate and water. A different extracts obtained were subjected to phytochemical characterization by high performance liquid chromatography (HPLC) comparing wavelengths of maximum absorption of the extracts with characteristic wavelengths found in the literature in order to determine the presence of compounds such as phenols, tannins and anthocyanins, which are generally associated with antioxidant activity evaluated. In addition to this, the determination of total phenols present in the extracts obtained was carried out in order to acquire more information about the possible antioxidant activity of each of them. The antioxidant activity evaluation was carried out through the electron capture methods DPPH (2,2-diphenyl-1-picrilhidracilo) and ABTS (2,2 'azinobis-(3-ethylbenzothiazoline)-6-sulfonic acid) and ABTS, taking as a positive control ascorbic acid solutions and gallic acid at 50, 100 and 150 ppm. This was determined after half inhibitory concentration (IC50) of the extracts promising. Getting the extract in ethyl acetate (PgAEF) and the aqueous extract (PgAF) were the most promising for the assessed activity with an IC50 of 5207 ppm and 3912 ppm respectively. Antioxidant capacity obtained by both methods of electron capture is correlated with the concentration of total phenols present in the extracts tested.