A survey and a formalized phytosociological classification of the marsh vegetation of the class Phragmito-Magno-Caricetea in central Italy is presented. Formal definitions of the majority of wetland associations recorded from the Italian territory were defined using the Cocktail method and applied to a large data set of vegetation plots extracted from the database VegItaly (hosted by the web database system "anArchive"). A total of 43 associations belonging to seven alliances and four orders were recognized. Detrended correspondence analysis (DCA), species indicator values and altitude were used to visualize ecological differences between the associations. Altitude, nutrient status and soil reaction were identified as the main environmental gradients responsible for diversification and distribution of the Phragmito-Magno-Caricetea communities in central Italy.