Altitudinal enclaves of rainforest are fragile and highly disturbed ecosystems located in high-altitude plateaus and mountains that are surrounded by Caatinga dry forest. Regardless of its biological importance, few studies regarding dung beetle assemblage were performed in an altitudinal enclave of rainforest. The aim of this study was to describe the structure of dung beetle assemblage from an altitudinal enclave of rainforest in the municipality of Triunfo, Pernambuco, Northeastern Brazil. Dung beetles were surveyed in the beginning of the rainy season using pitfall traps baited with excrement. Beetle diversity patterns were subsequently explored using Hill numbers. A total of 217 individuals belonging to 13 species and nine genera were recorded, and Dichotomius carbonarius (Mannerheim 1829), Uroxys bahianus Boucomont 1927, and Eurysternus nigrovirens Génier 2009 were the most abundant species. According to Hill numbers, there were five abundant species and three dominant species in the dung beetle assemblage. Also, there were two distinct beetle assemblages in the region of Triunfo, being most of the species commonly collected in Caatinga dry forest, as Deltochilum verruciferum Felsche 1911, Deltochilum sp., and U. bahianus. This study contributes to the scarce knowledge regarding diversity of dung beetles that inhabits altitudinal enclaves of rainforest of Northeastern Brazil, with a total of 43 species being currently recorded in such forests.