Focused on the project of construction of the common cross-border hospital of Puigcerdà (Spain), this paper deals with the difficulties of cross-border cooperation in Europe. After providing a presentation of the context (first part), the paper presents the rise of the project (second part), its difficulties and the stakes involved in health care provision as well as territorial organization at several scales (third part). Results show that the project is supported by local key actors, some of them having exercised national responsibilities. Moreover, the territorial cohesion across the border and the sense of common identity as well as complementarities in health care facilities in French and Spanish Cerdanya are other positive factors. But these particular local factors have to be considered with the contrasts between French and Catalan health care systems. This contradiction may explain the slowness in realizing the project. To summarize, this example of a common hospital project suggests that administrative, statutory and financial aspects are major obstacles for cross-border health care cooperation.