Evaluated and compared the support provided by family members and friends for adolescents' diabetes care. Family and friend support also were examined in relation to other measures of social support, to demographic variables (age, gender, duration of diabetes) and to adherence. Using a structured interview, 74 adolescents with diabetes described the ways that family members and friends provided support for diabetes management (insulin shots, blood glucose monitoring, eating proper meals, exercise), and for helping them to "feel good about their diabetes." Families provided more support than friends for three management tasks (insulin injections, blood glucose monitoring, meals); this support was largely instrumental. In contrast, friends provided more emotional support for diabetes than families. Greater family support was related to younger age, shorter disease duration, and better treatment adherence. Implications of the findings include encouraging parents to remain involved in adolescents' treatment management, and involving peers as supportive companions for meals and exercise.