The native tropical seaweed Kappaphycus alvarezii from the Indo-Pacific region has been introduced in manycountries because it is the main source of raw material for the carrageenan industry. In Brazil, K. alvarezii aquacultureis allowed in 300 km of the southeastern coast. The aim of this study was to analyze the risk of invasionof this species along the entire Brazilian coast to design public policies and to minimize environmental risks associatedwith aquaculture.