Having diabetes creates a lifelong trajectory of negative effects physically, and psychosocially. In some sense, because of the severity of the possible associated physical conditions and the demands of management, diabetes is the quintessential chronic illness. Practitioners in a variety of settings are likely to encounter clients with diabetes from across the lifespan. This chapter provides the available best practices for psychosocial interventions found to promise efficacy in this work. As with other illnesses discussed in this text, effective practice requires knowledge of the prevalence, and the disease itself, in addition to the psychosocial stressors attendant to the disease. Thus, this chapter discusses the prevalence of diabetes, and the condition and the behavioral and psychosocial factors of having diabetes. Following this discussion, the 20 studies evaluating interventions identified in the present systematic review study and that met the criteria of the present research are explicated. Last, implications for practice and future research, a glossary of relevant terms, and a scenario for discussion conclude the chapter.