The purpose of this study was to investigate the anthocyanins stability of Vaccinium myrtillus L. fruits methanolic extract during heating over the temperature range 50-100ºC. The obtained results indicate that the monomeric anthocyanins degradation followed first-order reaction kinetics. The rate constant (k) for anthocyanins degradation, the corresponding half-life values (t1/2) and the activation energy (Ea) were also calculated. The anthocyanins stability during storage was determined at -18, 4 and 25 ºC. Antioxidant activities of the extract after thermal exposure (90 and 100ºC) and after 4 months of storage were also evaluated using DPPH radical scavenging assay.