The introduction of non-native species in inland waters is one of the main threats for aquatic biodiversity. Introduced species may compete for resources, prey on native fauna, spread diseases and parasites. The channel catfish Ictalurus punctatus (Siluriformes, Ictaluridae) was first described by Rafinesque 1818 in the United States and is widely distributed in North America, south Canada and north-east Mexico. This species adapts easily to new environmental conditions, is tolerant to different habitats, and is grown easily in aquaculture, which turns it into a potential invader of natural aquatic environments. The introduction of I. punctatus occurs in Brazil since 1980, and this is the first record of its occurrence in the Rio dos Sinos basin, Brazil. A female adult catfish was captured during a survey in the main channel of the Rio dos Sinos (29º 44' 14.04" S and 51º 05' 11.08" W). Most probably the captured individual is an escapee from nearby aquaculture facilities.