Background: The rehabilitation counseling process is dependent on strong working alliance. However, few studies have been conducted to understand factors that affect the development of working alliance in rehabilitation counseling. Objective: The purpose of this paper is to examine interpersonal theory as a way of understanding the development of working alliance in rehabilitation counseling. Methods: We provide a background for the foundations of interpersonal theory and the related mathematically based interpersonal circumplex model. We propose that interpersonal theory is a useful framework for rehabilitation counselors to better understand the development of working alliance and client outcomes. Findings: Interpersonal theory is based on the belief that people's interactions with others determine their sense of security, sense of self, and motivations. People use interpersonal interactions to meet their personal psychological needs. Interpersonal theory provides a framework for understanding why individuals with disabilities might experience interpersonal difficulties when working with a counselor, seeking employment, or navigating different relationships. Conclusions: Through understanding interpersonal theory, rehabilitation counselors can be more aware of their clients' interpersonal strengths or problems, allowing them to better prepare their clients to be successful in their goals.