A floristic survey of the Asteraceae was carried out at the Pedra do Lagarto, Santa Maria, central region of Rio Grande do Sul state, Brazil. Field expeditions were conducted from August 2014 to September 2015. A total of 106 species were recorded, with 6 listed in the endangered species list of the state of Rio Grande do Sul: Moquiniastrum mollissimum (Malme) G. Sancho, Trixis pallida Less, Calea clematidea Baker, Aldama megapotamica (Malme) Magenta & Pirani, Chromolaena angusticeps (Malme) RM King & H. Rob., and Isostigma peucedanifolium (Spreng.) Less. This paper presents a list of recorded species from this site.