In the present study the phenolic (Folin-Dennis) and flavonoid (colorimetric assay) constituents and the antioxidant activity of Pterodon emarginatus seeds were investigated in several samples prepared with different extraction procedures: essential oil (EO) using a Clevenger-type apparatus; hexanic (HF), ethyl acetate (EAF), buthanolic (BF) and methanolic (MF) fractions using Soxhlet extraction, and extracts (1 g/extract) obtained from different methods: reflux 80 C/30 min, ultrasound/30 min, static maceration/48 h and heating plate 100 C/45 min. These extracts were prepared using water or ethanol/water at 30: 70 v/v, 50: 50 v/v or 70: 30 v/v. Antioxidant activity [ 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH)] was tested only in the fractions obtained from Soxhlet extraction. The extract obtained from reflux using ethanol/water (70: 30, v/v) showed the highest phenolic constituents level. The EAF, BF and MF showed DPPH scavenging activities with IC50 = 163.22, 18.89 and 10.15 mu g/ml, respectively.