Patients with diabetes commonly feel overwhelmed, frustrated, or "burned out" by the daily hassles of disease management and by the unending, often burdensome self-care demands. Many report feeling angry, guilty, or frightened about the disease, and often are unmotivated to complete diabetes self-care tasks. The toll of short- and long-term complications can make the disease even more burdensome. Not surprisingly, it is a consistent finding across studies that diabetes is associated with impaired health-related quality of life (HRQOL), measured in a variety of different ways. Importantly, the relationship between HRQOL and diabetes appears to be bidirectional. Both medical and psychosocial aspects of diabetes may negatively affect HRQOL; in turn, impaired HRQOL may negatively influence diabetes self-management. Unfortunately, the concept of HRQOL in diabetes remains unclear, making precise evaluation and intervention difficult. There is growing agreement that the focus of HRQOL assessment should be on the subjective burden of symptoms, not merely on the presence of objectively identifiable problems. Proper evaluation should include both generic and diabetes-specific elements of HRQOL. In this article, a comprehensive multidimensional model of HRQOL in diabetes involving six major components is introduced and described. Representative self-report questionnaires that may be valuable in assessing these components are also presented. Once the patient's most important HRQOL issues have been identified and prioritized, appropriate intervention becomes possible. The good news is that there are now a growing number of research-based interventions available for addressing almost all of the HRQOL impairments that may occur.