Using the method proposed by Herrero and Villar (2012), in which multiple distributions of categorical data are evaluated and ordered, we study the evolution of nationalist identity in Spain based on opinion surveys regarding the state of Spanish Autonomous Communities (AC) carried out by Spain’s Centre for Sociological Research (CIS, acronym in Spanish) since 1998. We construct two indices based on the value vectors of the Herrero-Villar method that describe the evolution of nationalist identity in each of Spain’s ACs, with respect to the rest of the ACs in each of the surveys, and with respect to their own AC across the surveys