The environment influencing hospitals in the health industry is quite complicated, and despite the high volume of inputs, the functions that occur at purchasing level are very intricate. The reason that the feedback mechanism of health services is not organized completely, and thus another reason that the health system is quite complicated, is diversification of inputs and the consequent rising volume of inputs from the environment, and high dependency on the environment. Governing the demands and pressures of the environmental actors and reorganizing them for its own benefit are only possible for the business, depending on how much power it has in the interdependent relationship. Therefore, it is necessary to clarify the role of power as a concept when analyzing these environmental relationships in order to elucidate the behaviors of organizations. This study addresses power relations in the framework of resource dependency theory. The "power and dependency relationship" of the actors that are influential in purchasing decisions regarding clinics at a private hospital where physicians, who are experts in their field work, is the proposal of this research. The matter of which actors (hospital upper management, purchasing department, relevant expert physicians) have an influence on purchasing decisions and mutual relations are discussed in the context of power.