A B S T R A C TRecently, Korean medical service centers have been impelled to achieve their goals in the rapidly changing healthcare environment. Therefore, such centers are required to identify and even predict what their patients really want. Trends in the Korean healthcare market have changed from service that is provider-centered to care that is patient-oriented (client-oriented), also described as patient-centered care. Since medical treatment techniques are similar throughout all medical centers, they must now focus on not only treatment techniques but also service providers' (doctors and nurses) emotional displays. To manage emotions that medical service providers show clients, medical centers are using explicit or implicit display rules. In order to follow these display rules, service providers usually choose two kinds of strategies: surface acting and deep acting. Both kinds of acting that service provider's display can result in client satisfaction. Even if clients hardly experience these as authentic, they can still experience rapport when encountering adequate service-delivery time or frequent meetings with providers. When clients feel rapport with their service providers, this may lead to client satisfaction. The purpose of this study is to examine the clients' perceptions toward displays of medical service providers' emotions and also the relationship between these perceptions and rapport. In addition, how rapport is established between service providers and clients directly influences or mediates client satisfaction. The results show that the perception of deep acting has a positive effect on rapport, and rapport is fully mediated. Finally, the present study shows that rapport can be changed by the amount of encounter time, even if medical service providers express inauthentic emotions. This study uses 172 samples collected from patients who were hospitalized in a medical center. To analyze these samples, SPSS 18.0 and AMOS 18.0 were used to confirm overall model fits, EFA, CFA, and regression analysis was carried out to figure out the moderator effect. In addition, this study adopted several survey items from previous studies such as deep acting, surface acting, time and duration of interaction, and rapport and client satisfaction.