Ants are being widely studied in different Brazilian biomes due to their sensitivity to environmental changes. Therefore, in order to evaluate the effect of climatic variables on species richness, as well as the impact caused by vineyards on the epigeic ant fauna in the region of the Pampa biome, more specifically in the physiographic region of Campanha, in the state of Rio Grande do Sul, a survey was performed on three farms, for a period of 2 years. On each farm, samples were obtained within the vineyards and in the surrounding grassland vegetation, which is similar to that which preceded the cultivation of vines. Twenty pitfall traps were installed in each environment. A total of 70 species belonging to 24 genera and seven subfamilies were collected. The analysis confirmed that the species richness was influenced by temperature and rainfall, and that the vineyards behave like other agricultural systems, causing a significant change in the structure of the ant assemblage when compared to grassland areas.