The use of natural compounds to prevent oxidative damage in biological systems is becoming increasingly popular. Blueberries have been of specific interest because of their high antioxidant capacity. Anthocyanins were extracted from berries of Vaccinium angustifolium Aiton and Vaccinium myrtilloides Michaux at 79 degrees C in acidified ethanol with phosphoric acid as a solvent using a liquid/solid ratio of 10. Extracted anthocyanins were purified on a C-18 silica-packed column and analyzed by HPLC coupled to electrospray ionization mass spectrometry. Of the six common anthocyanidins, five were identified in the extracts, namely delphinidin, cyanidin, peonidin, petunidin, and malvidin, while pelargonidin was not found. The free radical scavenging effects of anthocyanins were evaluated using N,N-dimethyl-p-phenylenediamine method as well as their potential to mitigate in vitro low-density lipoprotein (LDL) oxidative damage. After 6h of incubation, the oxidation products formation such as that of conjugated dienes, trienes, and hexanal was inhibited up to 60%. Based on these data, we concluded that anthocyanins from V. angustifolium and V. myrtilloides of Quebec possess the ability to inhibit in vitro LDL oxidation.