Arbuscular mycorrhizal fungal (AMF) communities present in the rhizosphere are critical to plant and ecosystem function. We tested the hypothesis that contrasting coastal ecosystems, dune and restinga, alter the correlations between the spatial patterns of these fungi and the diversity of plants. We evaluated the diversity of plant and AMF communities close to its rhizospheres in Peró Beach, Cabo Frio, State of Rio de Janeiro, during rainy and dry seasons in 2014. A total of 35 plant species belonging to 34 genera and 23 families were recorded. The species Ipomoea imperati, Stenotaphrum secundatum, Hydrocotyle bonariensis and Remirea maritima were the most common. Higher plant species richness was found in restinga over dune habitats in both seasons. Multivariate analysis revealed that in dunes, the seasons shaped more differences between the relations AMF-plants. In the restinga, the relationship between plants and AMFs was not clearly related to the seasons or the species of plants. The fungi Racocetra coralloidea and Dentiscutata scutata were found close to the rhizosphere of S. secundatum and H. bonariensis exclusively in dunes, while the fungus Funneliformis verruculosum was present close to the rhizosphere of these same plants exclusively in restinga. Further work should focus on AMF communities in roots of the dune and restinga plants to increase our understanding of plant-AMF associations in these understudied ecosystems.