We present the floristic survey of ferns and lycophytes from the “Parque Estadual Turístico do Alto Ribeira” (PETAR), a remnant of Atlantic Rain Forest of Southeastern Brazil, in São Paulo state. Besides a complete list of species, we also provide information on habit, geographic distribution, and conservation status. Among the 237 taxa, there are 235 species, one variety and one hybrid, distributed in 29 families and 74 genera. Ferns are represented by 223 taxa, whereas the lycophytes were represented by 14. The most representative families are Polypodiaceae (31 spp.), Pteridaceae (29 spp.) and Dryopteridaceae (28 spp.). The most diverse genera are Thelypteris (23 spp.), Asplenium (19 spp.), Elaphoglossum and Blechnum (10 spp. each). Noteworthy is the presence of Ctenitis anniesii, Dicksonia sellowiana, Elaphoglossum iguapense, E. prestonii, E. strictum, Thelypteris concinna, T. araucariensis and T. hatschbachii, all of them considered as endangered species in São Paulo state.