This chapter presents research of the approach of economics and sociology of conventions (EC/SC or convention theory) on the hospital as an institution. From this perspective, it is the conventions that bring the hospital to life and give it its meaning. The hospital is apprehended as a collective cognitive device on which actors rely to coordinate their care. It is also the place where patients know they can go if they have health problems or need medical technology. The hospital is central to patients’ perception of the healthcare system and how it works. It is also central to doctors’ referral of patients to other professionals and mobilizes it as a cognitive resource. The hospital is also rooted in conventions, as it is subject to numerous and often contradictory interpretations. The hospital crisis is a crisis of normative representation of what it should be. The hospital is an important site of struggle to define the field of possibilities and identify what matters most. But what counts is not at all the same for patients, carers and political decision-makers. The first part of this chapter explains how convention theory approaches hospital transformations, while the second part examines how it interprets the latest reforms through the concept of the power of valorization.