OBJECTIVE: To develop and test a youth-report measure of collaborative parent involvement in type 1 diabetes management. METHODS: Initial item development and testing were conducted with 81 youths; scale refinement and validation were conducted with 122 youths from four geographic regions. Descriptive statistics, Cronbach's alpha, and factor analyses were conducted to select items comprising the scale. Correlations with parenting style and parent diabetes responsibility were examined. Multiple regression analyses examining associations with quality of life, adherence, and glycemic control were conducted to assess concurrent validity. RESULTS: The measure demonstrated strong internal consistency. It was modestly associated with parenting style, but not with parent responsibility for diabetes management. A consistent pattern of associations with quality of life and adherence provide support for the measure's concurrent validity. CONCLUSIONS: This brief youth-report measure of parent collaborative involvement assesses a unique dimension of parent involvement in diabetes management associated with important youth outcomes.