OBJECTIVE -To prospectively assess the relation between marital relationship domains (i.e., intimacy and adjustment) and health-related quality of life (HRQoL) and glycemic control of individuals with diabetes.RESEARCH DESIGN AND METHODS -A previous cross-sectional study assessed the relationship between marital quality and adaptation to diabetes for 78 insulin-treated adults. Each participant completed two marital quality measures (Spanier Dyadic Adjustment Scale and Personal Assessment of Intimacy in Relationships Scale) at time 1 (T1). A total of 61 subjects were contacted two years later (time 2 [T2]) and re-administered four HRQoL measures (Diabetes Quality of Life Scale, Medical Outcomes Study Health Survey-SF36, Problem Areas in Diabetes Scale, and Positive and Negative Affect Schedule). Glycemic control was assessed by HbA 1c . Demographic data (age, sex, type and duration of diabetes, years married, other medical problems, family history, and years of education) were gathered from charts and questionnaires. Linear regression analyses were used to assess the ability of the two marital measures at T1 to predict HRQoL at T2, controlling for confounding HRQoL and baseline subject variables.RESULTS -Both of the marital quality measures at T1 were prospective predictors of aspects of HRQoL at T2. Less diabetes-related distress at T2 was predicted by better marital adjustment at T1. Greater satisfaction with aspects of the diabetes care regimen at T2 was predicted by better marital adjustment and greater perceived marital intimacy at T1. Neither marital measure predicted general HRQoL or glycemic control.CONCLUSIONS -For insulin-treated adults with diabetes, quality of marriage prospectively predicts diabetes-related quality of life. This study highlights the sensitivity of diabetesspecific measures. Future work should explore the value of interventions that target the spouse and/or couple.