The different political, social, institutional and economic relations that may be established between two border cities have raised an interesting theoretical debate on how to name this particular cooperation. In this contribution we will elaborate a literature review on the subject, and choose one specific concept we believe is useful for the analysis of specific cases: border-crossing cities. This concept is linked to a theoretical model proposed to study cooperation projects in border urban areas, based on four elements: common territory, institutional framework, activities, symbols and communication. Looking specifically to the European context, we have chosen the so-called Eurocidade ChavesVerín, one of the first experiences in the Iberian Peninsula. The analysis is organised around the factors identified in the theoretical model; we will follow a quantitative and qualitative methodology (official documentation, fieldwork and non-structured interviews). The final results of the research suggest that we are dealing here with a case of border-crossing cities, although there still exist several challenges to improve cross-border cooperation. © 2015, Universidad de Granada. All rights reserved.