Frail, older care recipients are often thought of as individuals with a decreased mastery of everyday life skills. Various authors have proposed to acknowledge a relational dimension of mastery, defined as the ability to maintain control over one's life with the help of others. This study explores how frail, older adults experience relational aspects of mastery and the role of their informal caregivers in maintaining these aspects of mastery over the care process. Qualitative interviews (N = 121) were conducted in 2016 with potentially frail, community‐dwelling older adults participating in the Detection, Support and Care for Older people: Prevention and Empowerment (D‐SCOPE) project. A secondary analysis of 65 interviews reveals that, according to frail, older adults, informal caregivers contribute in various ways to the preservation of their mastery. This differs across the four elements of care: caring about (attentiveness), taking care of (responsibility), care‐giving (competence), and care‐receiving (responsiveness). However, in some cases, older adults experienced a loss of mastery; for example, when informal caregivers did not understand their care needs and did not involve them in the decision, organisation, and provision of care. A relational dimension of mastery needs to be acknowledged in frail, older care recipients since stimulating mastery is a crucial element for realising community care objectives and person‐centred and integrated care.