Restingas are mosaics of plant communities living on marine sand deposits of the late Quaternary period, located between the sea and the Atlantic Forest. This study presents the diversity of the vegetation of coastal sand dunes in the southeastern coast of Brazil. A floristic survey and bibliographic review of the nine restinga regions of Rio de Janeiro state was carried out, and information is presented about the habit, life form, dispersion syndrome, distribution, and biome occurrence of each species. Ninety-eight species were recorded, distributed among 81 genera and 38 families, of which the most diverse are Asteraceae (12 species), Poaceae (12 species), Fabaceae (11 species), and Rubiaceae (6 species). The majority of species have herbaceous habits and predominantly are camephyte-autochoric species. They present wide geographical distributions or are restricted to just some Brazilian states and are more similar to the Atlantic Forest biome.