Resumo. Entre as espécies de formigas economicamente importantes, devido aos danos que muitas vezes causam à agricultura, as mais significativas são as formigas-cortadeiras por possuírem o hábito de cortar e transportar fragmentos vegetais diversos para os seus ninhos subterrâneos. O objetivo deste estudo foi caracterizar alguns aspectos ecológicos de Atta sexdens piriventris Santschi no município de Capinzal, estado de Santa Catarina, Sul do Brasil. O material de origem vegetal transportado pelas formigas apresentou como característica folhas verdes/frescas 57%, folhas secas 23%, pedaços de frutos 7%, sementes 7% e flores 3%. Já os de origem animal tiveram uma representação de 3%, e eram compostos por pedaços de insetos. A média de distância percorrida pelas formigas em busca do substrato foi de 12,54 m. Palavras-chaves:Forrageio; Myrmicinae; Ninhos; Substratos. Ecological Aspects of Atta sexdens piriventris Santschi (Hymenoptera: Formicidae) in the Municipality of Capinzal, Santa Catarina, BrazilAbstract. Among the economically important species of ants, due to the damage they often cause the agriculture the most significant are the leafcutting ants because they have the habit of cut and transport various plant fragments to their underground nests. The objective of this study was characterized some ecological aspects of Atta sexdens piriventris Santschi in the municipality of Capinzal, Santa Catarina state, Southern Brazil. The plant material transported by the ants was 57% of green leaves, 23% of dried leaves, 7% of fruits, 7% of seeds, 3% of flowers and only 3% of animal parts, mostly compounds by insect parts. The average distance walked by the ants in search of the substrate was 12.54 m.