['To devise and implement a structured intervention for integrating peers into diabetes care in a healthy and adaptive manner.', 'Adolescents with diabetes (n = 21) and their best friends (n = 21) participated in a group intervention aimed at increasing diabetes knowledge and social support of diabetes care. Measures of social support, knowledge about diabetes and support, diabetes functioning, and social functioning were obtained prior to and following intervention.', 'Following the intervention, adolescents and their friends demonstrated higher levels of knowledge about diabetes and support, as well as a higher ratio of peer to family support, and friends demonstrated improved self-perception. Parents reported decreased diabetes-related conflict.'] Do a peer group intervention for adolescents with type 1 diabetes and their best friends?