PURPOSE: The purpose of this study was to evaluate how social support and race/ethnicity were associated with diabetes self-care behaviors and clinical outcomes. METHODS: Using the cross-sectional 2005-2006 National Health and Nutrition Examination Survey (NHANES), the authors examined white, black, and Latino respondents who self-reported a diabetes diagnosis (n = 450), estimating the associations of social support on diabetes outcomes. The primary exposure was a social support index (0-5), which assessed the number of sources of support in one’s life. Outcomes were self-care behaviors (controlling weight, exercising, controlling fat/caloric intake, checking feet, and self-monitoring blood glucose) and intermediate clinical outcomes (hemoglobin A1C, diastolic blood pressure, and low-density lipoprotein [LDL]). RESULTS: There were no differences in social support by race/ethnicity. The authors observed several significant race/ethnicity by social support interactions in adjusted models, controlling for age, gender, education, self-reported health, depression, functional disability, insurance status, and insulin use. Among blacks, social support was associated with controlling weight (odds ratio [OR] = 1.55, P = .03), exercising (OR = 1.38, P = .03), controlling fat/calories (OR = 1.84, P = .03), and lower diastolic blood pressure (beta = -3.07, P = .02). Among whites, social support was associated with lower LDL (beta = -9.45, P = .01). No significant effects were noted for Latinos. CONCLUSIONS: The relationship of social support with diabetes management differed by race/ethnicity, with the strongest findings among blacks. Social support may be influential for maintaining self-care behaviors among blacks and controlling lipid levels among whites.