3-Hydroxyindole was isolated from the EtOH extract of fruits of Aristotelia chilensis during analyses by HPLC/MS and GC/MS and identified by its mass fragmentation pattern and spectrophotometric data. Additionally, this extract showed an interesting antioxidant activity in DPPH, crocin and TBARS assays. The presence of this type of compound in this fruit species permits us to explain its strong antioxidant activity and its important part in the biosynthetic pathway of phenolic and alkaloid compounds in this plant. Therefore this compound could be useful for the development of future nutraceutical and antioxidant protective agents.