Participation in activity is essential for the psychological well-being of people with dementia. The potential benefits of home-based activity programmes may depend on family carers, but little is known about their experience. This study aimed to elicit carers' experiences of involving the person with dementia in activity. Thirty in-depth interviews (i.e. initial and follow-up) were carried out with 15 co-resident carers of people with dementia who were recruited through local community mental health teams. Data were analysed using a grounded theory method. Overall, findings from initial interviews were taken back to the participants at the follow-up interviews. Five activity patterns were identified, which ranged from their usual activity patterns along a continuum through recognizable, illogical, irresponsible and finally reaching a dispossessed pattern. Carers used particular strategies and experienced particular emotional responses along this continuum. This work highlights the complex, temporal and dynamic nature of family carers' involvement in activity engagement. Clinician's interventions could be enhanced by: (1) recognizing the long-term experience of carers in decision making; (2) understanding the strategies used; (3) allowing carers to talk through and share their experiences in a non-judgmental way; (4) ensuring that carers are happy with any suggested interventions.