Syntaxonomic classification of reed and tall sedge beds, grasslands, heathlands, and scrub vegetation is proposed for the Podyjí National Park in south-western Moravia in the Czech Republic, the Thayatal National Park in north-western Lower Austria, and some adjacent areas. Vegetation of the following phytosociological classes is described: Phragmito-Magnocaricetea (4 communities), Molinio-Arrhenatheretea (13 communities), Koelerio-Corynephoretea (3 communities), Calluno-Ulicetea (3 communities), Festuco-Brometea (9 communities), Trifolio-Geranietea (5 communities), and Rhamno-Prunetea (4 communities). The communities are documented by phytosociological relevés, analysed using detrended correspondence analysis and compared by Ellenberg indicator values. Seven vegetation complexes of semi-natural or natural terrestrial treeless vegetation are distinguished and described.