Calafate ( Berberis microphylla ) is a native berry grown in the Patagonian area of Chile and Argentina. In the present study the phenolic composition and antioxidant activity of its fruits were studied and also compared with data obtained for other berry fruits from southern Chile including maqui ( Aristotelia chilensis ) and murtilla ( Ugni molinae ). Polyphenolic compounds in calafate fruit were essentially present in glycosylated form, 3-glucoside conjugates being the most abundant anthocyanins. The anthocyanin content in calafate berries (17.81 +/- 0.98 micromol g(-1)) and flavonol level (0.16 +/- 0.01 micromol g(-1)) are comparable with those found in maqui (17.88 +/- 1.15 and 0.12 +/- 0.01 micromol g(-1), respectively); however, maqui shows lower flavan-3-ol concentration than calafate (0.11 +/- 0.01 and 0.24 +/- 0.03 micromol g(-1), respectively). Maqui and calafate show high antioxidant activity, which correlates highly with total polyphenol content and with anthocyanin concentration.