Tropical highland blackberry (Rubus adenotrichus Schltdl.) is a good source of antioxidants and contains appreciable levels of phenolic compounds, mainly ellagitannins and anthocyanins. This study examined the influence of three ripening stages on phenolic contents. Major anthocyanin pigments increased from 0.20 (red fruit) to 1.34 mg g_1 fresh weight (FW) (fully ripe fruit), whereas ellagitannins and ellagic acid derivatives dropped from 3.8 to 2.2 mg ellagic acid equivalents g_1 (FW). Flavonols also dropped from 5.1 to 2.0 mg quercetin equivalents 100 g_1 (FW). Consequently, values for total phenolic compounds ranged from 5.8 to 5.2 mg gallic acid equivalents g_1 (FW), showing no specific trend. Antioxidant activity (H-ORAC) increased from 38.29 to 64.00 lmol of Trolox equivalents g_1 (FW) during ripening. When compared with other commercial cultivars, R. adenotrichus stands out for high H-ORAC value, although comparatively it possesses low anthocyanin content and average total phenolic content.