The aim of this study was to identify how the family care of people living with dementia could be supported to make reliance on family care sustainable in the long term despite the impact of stress. A Realist Evaluation (Pawson & Tilley, 1997) was conducted to investigate this aim. An initial review established ‘coping’ as a primary means of mediating stressors associated with caregiving. However, there was a need to specify which coping approaches/strategies are most effective. In‐depth interviews were conducted with a purposive sample of family carers (n = 18) in a suburb in North East England from 2016 to 2017. Analysis of the data revealed ‘social coping’ (SC) that included an emotional support component as a critical mediator of family carer stress. Several key hindrances to the utilisation of SC, including underpinning causal factors, are explicated. Ways in which these hindrances might be overcome are discussed and guidelines introduced for how family carers, formal providers and practitioners can facilitate SC as a critical coping strategy in sustaining the family care of people with dementia over the long term.