The present study analyzed the composition, species diversity, and altitudinal distribution of rust fungi (Uredinales) collected in the Parque Nacional do Itatiaia, Brazil. Results were compared with other Atlantic Forest locations, the Sao Paulo Cerrado and some other tropical regions. The Uredinales collections were made over the course of two years, covering the states of Rio de Janeiro and Minas Gerais, from 500 to 2600m above the sea level. The Uredinales Biota is composed of 38 genera (32 teleomorphs and 6 anamorphs) and 207 species, 178 of which were teleomorphic and 29 anamorphic. The genera Puccinia, Uromyces and Phakopsora contained a high number of species (58% combined). A hundred and ninety-two hosts belonging to 63 botanical families were recorded. The rust/host ratio for ten of the richest families in number of species was 1:8. A high similarity (50%) was found between two altitudinal ranges. The results provide a strong additional argument for the need to preserve and continue studies in such areas