We describe the composition, abundance and some natural history aspects of the snake community of Parque Nacional de Sete Cidades (PNSC), Municipality of Piracuruca, State of Piauí, northeastern Brazil, and compare its composition with those of nine other localities in Brazil. We used three sampling methods: time-constrained search, pitfall traps with drift fence and incidental encounters, and recorded 87 snakes, belonging to five families (Boidae, Colubridae, Dipsadidae, Elapidae, Viperidae), 18 genera and 24 species. The dominant species was Thamnodynastes sp. A (13.1%), followed by Oxyrhopus trigeminus and Micrurus ibiboboca (10.3%). There was a predominance of terrestrial species and those with diurnal activity. The typical cerrado showed the greatest species richness, and the lowest richness were recorded in the campo limpo (grasslands) and cerrado rupestre (rocky grasslands). Species composition of the PNSC community was more similar to those of the Cerrado-Caatinga transition zone and the Caatinga,