This paper aims to explore and describe the way in which start-up firms are grouped into industries. To this end, a quantitative research approach is presented, applying a social network analysis to a sample of Pacific Alliance start-ups, which were recorded in CrunchBase, considering their operational activities as linkage criteria. In this way, this document offers a new application to social network analysis to demonstrate the need for a different way of classifying start-ups that goes beyond the industry boundaries established by the traditional classification systems. It also shows that Pacific Alliance start-up industries are structured according to a pattern of dominant activity, applied technology and specific use. In addition, there is a concentration on mature or declining start-up industries, while growing industries are left in second order.