Antioxidants are compounds that inhibit combustion (oxidation) processes. Antioxidants are vital components of our body, which can be obtained in part through plant nutrition. Therefore, it is very important to study species that have significantly higher antioxidant capacity than other species. The aim of the study was to investigate the antioxidant capacity of total polyphenols (TPC) of European mistletoe (Viscum album L.) leafy shoots collected from different species of trees (black locust, European ash, white poplar, field maple and black walnut) based on different methods; DPPH (2,2-diphenyl-1-picrylhydrazyl), FRAP (ferric reducing antioxidant power) and TPC (total phenolic contents). The results proved that the antioxidant effect of leafy shoots from European ash (Fraxinus excelsior) against hydroxyl radicals (ROS) showed significantly higher values than those of the other four tree species. We found that the DPPH, FRAP and TPC methods show significant differences in antioxidant effect of European white mistletoe leafy shoots on the studied tree species and tea brands. However, the FRAP method shows higher sensitivity for trees but for tea brands, the DPPH method is more sensitive. The reason for the difference might be explained by the different methods of drying. In the future, we consider it feasible to plant ash groves at an altitude of at least 80 m above sea level in a closed area, where we can start growing European white mistletoe as an herb. Based on the results obtained European white mistletoe can be recommended as an herb to natural medicine for supplementary treatment of several cancer diseases.