Background: The right of people with disability to be self-determining, to live a life of their choosing, is increasingly recognized and promoted. For adults with intellectual disability, support to enable self-determination may be required. This is often provided by family, yet little is understood about the experience of providing such support. Methods: An interpretative phenomenological analysis (IPA) of eight individual, semi-structured interviews with mothers was conducted, to understand the meaning given to their experience of supporting self-determination of their adult son or daughter with intellectual disability. Results: Three superordinate themes were identified: (a) support context; (b) continuum of support roles; and (c) mother's personal concerns. Conclusion: Mothers of adults with intellectual disability experience an ongoing sense of responsibility to balance competing rights and concerns as they support self-determination. This complex, interdependent relationship results in roles that may facilitate, guide, influence and at times restrict choice and control.