We used the Dpph method to assess in vitro the antiradical activity of extracts from the roots, leaves and fruits of six Rumex L. (dock) species. Data from preliminary screening indicated that all the tested extracts showed antioxidant properties. The degree of antiradical activity depended upon the plant part. Fruit extracts from R. hydrolapathum Huds., R. obtusifolius L. and R. confertus Willd. showed stronger antiradical properties than the other tested material. We also determined tannin content levels in the extracts and their correlation with antioxidant activity.