Lycophyta and Polypodiophyta have been used by humans worldwide since ancient times, yet little has been documented. This paper analyzes and discusses the different uses of these plants in three Priority Terrestrial Regions (PTR) of conservation in the state of Oaxaca in Mexico. Our objectives were to: 1) document the traditional knowledge and uses of Lycophyta and Polypodiophyta among ethnic and mestizo groups; 2) analyze the variation in the use of taxa among these ethnic and mestizo groups, in terms of altitudinal distribution and type of vegetation in habitats supporting these species. Fifty species and two varieties of useful Lycophyta and Polypodiophyta from 29 genera and 15 families, were recorded. Mazatecs, Zapotecs, and Mixes are the ethnic groups with the greatest number of records of useful species from these taxonomic groups. More than 68% of such species are recognized with common names in the local languages. There are two conditions of useful plants: 1) among species used by at least four ethnic groups, how do the uses vary from two to four; 2) related to species with at least four categories of use, which are used by few ethnic groups. More than half of the species are named in at least one language, which reinforces the fact that species are recognized, valued, and important in people's daily lives, including traditional ceremonies, beliefs. Eight categories of use were documented, with medicinal, ornamental, and handcraft being the most represented. 80% of the useful Lycophyta and Polypodiophyta were distributed above 1000 masl, mainly in montane cloud forest, Quercus forest and Quercus-Pinus forest.