Quality of services is considered as one of the most important factors for customer retention as well as having a healthy business. In this paper, we present an empirical investigation to determine the most important factors influencing patients’ satisfaction in one of Iranian hospitals. The proposed model of this paper uses fuzzy analytical network process (FANP) to rank different factors. The proposed model considers four major criteria including employee, management as well as organization, physicians and nurses. Our survey indicates that management and organizational issues are the most important factors followed by issues associated with physicians, nurses and employees. In terms of management and organization, waiting time to receive services is the most important factor followed by geographic location of the hospital, peaceful and quiet environment and quality of services. In addition, our surveyed patients expected their patients to listen to them very carefully and this is the most important item. They also expect nurses to provide a fast and reliable response while they expect employees to treat them with respect.