Patient safety is compromised by medical errors and adverse events related to miscommunications among healthcare providers. Communication among healthcare providers is affected by human factors, such as interpersonal relations. Yet, discussions of interpersonal relations and communication are lacking in healthcare team literature. This paper proposes a theoretical framework that explains how interpersonal relations among healthcare team members affect communication and team performance, such as patient safety. We synthesized studies from health and social science disciplines to construct a theoretical framework that explicates the links among these constructs. From our synthesis, we identified two relevant theories: framework on interpersonal processes based on social relation model and the theory of relational coordination. The former involves three steps: perception, evaluation, and feedback; and the latter captures relational communicative behavior. We propose that manifestations of provider relations are embedded in the third step of the framework on interpersonal processes: feedback. Thus, varying team-member relationships lead to varying collaborative behavior, which affects patient-safety outcomes via a change in team communication. The proposed framework offers new perspectives for understanding how workplace relations affect healthcare team performance. The framework can be used by nurses, administrators, and educators to improve patient safety, team communication, or to resolve conflicts.