OBJECTIVE Prior research has shown that less social support is associated with increased mortality in individuals with chronic illnesses. We set out to determine whether lower propensity to seek support as indicated by relationship style, based on attachment theory, is associated with mortality in patients with diabetes. RESEARCH DESIGN AND METHODS A total of 3,535 nondepressed adult patients with type 1 and type 2 diabetes enrolled in a health maintenance organization in Washington State were surveyed at baseline and followed for 5 years. Relationship style was assessed at baseline. Patients with a greater propensity to seek support were classified as having an interactive relationship style and those less inclined to seek support as having an independent relationship style. We collected Washington State mortality data and used Cox proportional hazards models to estimate relative risk (RR) of death for relationship style groups. RESULTS The rate of death in the independent and interactive relationship style groups was 39 and 29 per 1,000 individuals, respectively. Unadjusted RR of death was 1.33 (95% CI 1.12-1.58), indicating an increased risk of death among individuals with an independent relationship style. After adjustment for demographic and clinical covariates, those with an independent relationship style still had a greater risk of death compared with those with an interactive relationship style (hazard ratio 1.20 [95% CI 1.01-1.43]). CONCLUSIONS In a large sample of adult patients with diabetes, a lower propensity to reach out to others is associated with higher mortality over 5 years. Further research is needed to examine possible mechanisms for this relationship and to develop appropriate interventions.