This study provides the first contribution to the knowledge of the non-calcareous grasslands of the arenaceous sector of the Monti Sibillini National Park (central Italy). We conducted 55 relevés using the Braun-Blanquet phytosociological method and analysed the ecology of plant communities by Redundancy analysis using topographic variables and Ellenberg Indicator Values as predictors. We identified nine plant communities, belonging to four classes. Communities of and were found on acidic soils at higher elevations, those of were mainly associated with steeper south-facing slopes, while communities were associated with low altitudes and gentle slopes, semi-flat lands, and high soil nutrient and moisture values. We recorded a total of 410 taxa at the species and subspecies level, representing about 20% of the flora of the Monti Sibillini National Park. Some of these are of high conservation interest, e.g. , , , and . Eight species are new to the flora of Sibillini National Park.