baccharis dracunculifolia dc. is a brazilian native plant species that produce essential oil with several biological activities and cosmetic applications. this study aimed to evaluate the effect of seasonality on the yield, chemical composition and antioxidant activity of b. dracunculifolia essential oils during four seasons in southern brazil. the extraction of the volatile compounds was carried out by hydrodistillation and the analyses of chemical composition of the species were performed by gc-fid and gc-ms, while antioxidant activity was evaluated by the dpph method. the samples were separated into two main groups: i) winter and spring: high levels -pinene (15.58-16.15%) and ii) summer and autumn: high levels of (e)-nerolidol (17.81-21.68%). these results suggest that b. dracunculifolia essential oil presents higher levels of (e)-nerolidol during the summer and autumn and -pinene during winter and spring. the highest antioxidant activity (88.89%) was observed during the summer with a positive correlation with limonene (r = 0.977).