In 2016, the Economic Commission for Latin America and the Caribbean (ECLAC) and the World Association for Waterborne Transport Infrastructure (PIANC) organized the workshop “Inland navigation and a more sustainable use of natural resources: networks, challenges, and opportunities for South America”. The goal of the workshop was, among others, to provide a forum for initial technical meetings among South American experts and international experts, on the future inland waterways classification for South America; to collect and analyse information and data on inland waterways characteristics, fleet, traffic intensity and other relevant factors for the development of technical and operation parameters, harmonized at the regional level. This article summarizes the results of the group’s technical meetings and teleconferences on the main issues related to the classification, including: context, objectives and scope of the classification; overview of the existing classification systems in South America; first methodology proposal for the inland waterway classification for South America.