The mortino fruits (Vaccinium meridionale Sw) have attracted the interest of consumers due to its high content of polyphenolic compounds and antioxidant activity; however, there has been no assessment of changes during maturation and ripening. In this study, the changes in content of total polyphenols and total anthocyanins, and antioxidant activity were evaluated by TEAC-ABTS, TEAC-DPPH, FRAP and ORAC methods. The mortino fruit exhibit a double sigmoid growth curve with three differentiable stages of growth. The antioxidant activity and total polyphenols content presented maximum the 17 day for ORAC (27,116 TEAC/ 100 g FW) and 36 day for TEAC-ABTS (16,794 TEAC/ 100 g FW), TEAC-DPPH (5,502 TEAC/ 100 g FW), FRAP (1,289 AEAC/ 100 g FW) and total polyphenols (4,804 mg gallic acid/ 100 g FW). The final values was 6,446, 5,688, 1,763 TEAC/ 100 g FW for ORAC,TEAC- ABTS, TEAC-DPPH, 375 AEAC/ 100 g FW for FRAP and 1,373 mg gallic acid / 100 g FW for total polyphenols. The total anthocyanins content varied from 4.2 mg eq cyanidin-3-glucoside / 100 FW to 271.9 mg eq cyanidin-3- glucoside / 100 g FF at end of ripening.