The quality of the “patient-carer” relationship is the foundation of self-management support and has been shown to influence treatment outcome in relation to psychological and somatic illness, including diabetes. It has long been accepted within applied psychology that the quality of the client-therapist relationship—termed the working alliance—is of central importance to treatment outcome and may account for a significant degree of the overall treatment effect. Diabetes healthcare providers have recently expressed a need for further training in communication techniques and in the psychological aspects of diabetes. Could we take a page from the psychological treatment manual on working alliance in therapy to guide the diabetes healthcare provider in their role of supporting the person with diabetes achieve and maintain better metabolic control? This paper examines the role of the working alliance in diabetes care and offers a practical guide to the diabetes healthcare provider in establishing a working alliance with the person with diabetes in managing diabetes.