This paper describes the traditional mycological knowledge of the Nahua of San Isidro Buensuceso, on the slopes of La Malinche Volcano National Park, in the state of Tlaxcala, México. The results described in this paper were obtained through interviews with villagers selected at random; a free-listing technique was used to determine the cultural significance of the mushrooms of the region. A total of 48 species, which had 65 Náhuatl names and 40 in Spanish, were identified. Although San Isidro villagers consider mushrooms to be a natural resource mainly used for food, they also use them for medicine, insecticides and trade. This paper presents traditional information on the morphology, ecology, fenology and consistency of the mushrooms found around San Isidro. It proposes that, from a cultural perspective, Gomphus flocossus, Ramaria spp. and Boletus spp. are the most important species of the region.