Abstract Brazilian biomes, such as the Atlantic Forest, are hotspots for microbial diversity. Fungi at some stages of their life cycle can inhabit the interior of plants without apparent damage and are called endophytes. This study aimed to verify the culturable diversity of endophytic fungi present in the leaves of Miconia mirabilis in a conservation unit of the Atlantic Forest, in Northeast Brazil. A total of 273 endophytes were isolated, and 88 % of the estimated richness was recovered from 40 taxa with a Shannon diversity index of H′ = 2.79. The most abundant order was Xylariales (37.73 %), with Xylaria cf. cubensis being the most abundant species, followed by Glomerellales (14.65 %), Eurotiales (3.66 %), and Diaporthales (3.33 %). Additionally, a novel endophytic fungal species of Muyocopron was identified. Our results indicate the potential of endophytic diversity in the plants of tropical forests, reinforcing the need for further studies to better understand their ecological relationships.