AIM: To determine which factors other than child age play a role in the division and transfer of diabetes care responsibilities between parents and children with type 1 diabetes. DESIGN: Qualitative focus group study. METHODS: Across four sites in the Netherlands, 18 parents (13 mothers) of children (9-14 years) with type 1 diabetes participated in four focus groups in 2015-2016, as part of the research project 'Whose diabetes is it anyway?'. Qualitative content analysis and the constant comparison method were used to analyse the data. RESULTS: According to parents, the transfer process included both direct and indirect tasks, had different levels (remembering, deciding, performing), was at times a difficult and stressful process, and showed large variation between families. A large number of child, parent and context factors were identified that affected the division and transfer of diabetes care responsibilities according to parents. Both positive and negative consequences of the transfer process were described for parental and child health, behaviour and well-being. Parental final evaluations of the division and transfer of diabetes care responsibilities appeared to be dependent on parenting values. CONCLUSION: How families divide and transfer diabetes care tasks appeared to be affected by a complex interplay of child, parent and context characteristics, which had an impact on several parent and child domains. IMPACT: Parents struggle with the right timing of transfer, which calls for more support from diabetes nurses. The identified factors can be used as input for integrating a more family-based approach into current age-based guidelines, to improve regular care.