This study extends the Technology Acceptance Model (TAM) by incorporating relationship quality as a mediator to construct a comprehensive framework for understanding the influence on continuance intention in the hospital e-appointment system. A survey of 334 Taiwanese citizens who were contacted via phone or the Internet and Structural Equation Modeling (SEM) is used for path analysis and hypothesis tests. The study shows that perceived ease of use (PEOU) and perceived usefulness (PU) have significant influence on continuance intention through the mediation of relationship quality, consisting of satisfaction and trust. The direct impact of relationship quality on continuance intention is also significant. The analytical results reveal that the relationship between the hospital, patients and e-appointment users can be improved via enhancing the continued usage of e-appointment. This paper also proposes a general model to synthesize the essence of PEOU, PU, and relationship quality for explaining users' continuous intention of e-appointment.