The paper addresses the themes of the economic organization and of the role of the incentives of the different actors in the health care sector. In particular, the paper analyzes the peculiar context of the intramoenia regime, according to which health care services are provided within public hospitals by exclusive physicians, but on a market based logic. The paper evidences the limits of the traditional principal-agent approach in addressing the complexity of the intramoeniaregime and suggests the adoption of a more rich and integrated perspective of analysis, able to take into account the articulated contractual relations originating among the different actors.