Buenos Aires coastal dune systems undergo an accelerated process of human induced modification, causing loss of native plant species and changes in species composition, cover and/or abundance. We present a species list of vascular plants recorded in a region of dune landscape between Pehuen-có and Monte Hermoso localities, southern Buenos Aires Atlantic coast. The area comprises fixed and active dune systems, frontal dunes, sandy marine beach and an abrasion platform. Vegetation sampling was performed using line-transects perpendicular to the coastline. Vascular plants were identified and species cover percentage was estimated in 10 m x 10 m plots. 31 families and 75 species were registered. Asteraceae, Poaceae, and Fabaceae were best represented. Ten exotic taxa were found. Vegetation structure is associated to geomorphologic heterogeneity. The site preserves rich flora with high number of native vascular plants. The presence of Neosparton ephedroides was verified. Conservation guidelines are necessary to protect the local biodiversity.