Phenolic acids present in mistletoe plants collected from various hosts were analysed with the use of HPLC. The following numbers of compounds were found in the mistletoe plant material gathered from respective hosts: Sorbus aucuparia- 12 compounds; Acer plantanoides--14 compounds: Malus domestica, Pyrus communis and Populus nigra--13 compounds each; Quercus robur--15 compounds. Altogether 21 phenolic acids were chromatographically identified in the tested material. The compounds were either free or combined as esters or glycosides. Comparative chromatography revealed qualitative differences in the investigated compounds between the various plant materials. For example o-coumaric acid was only found in mistletoe hosted by Quercus robur. Digallic acid was only found in the plant material hosted by Acer plantanoides. Qualitative and quantitative composition of mistletoes hosted by Malus domestica and Pyrus communis showed considerable similarities as far as phenolic acids were concerned. Moreover. vanillic acid. absent in all other batches of plant material, seemed to be characteristic of the above mistletoes. Quantitative HPLC analysis demonstrated a considerable content of salicylic acid (39.55 mg%) in mistletoe hosted by Sorbus aucuparia. Apart from the above material, this compound was only present in small quantities in plants hosted by Populus nigra (15.63 mg%) and Quercus robur (2.63 mg%).