Background: Family members of children with developmental disabilities on average report poorer family functioning and mental health. Positive Family Connections is a co-produced, positively-oriented, family-systems support programme for families of children with developmental disabilities aged 8-13. We investigated experiences of Positive Family Connections, and the processes involved in change. Method: We conducted semi-structured interviews with eight family carers who took part in Positive Family Connections and nine facilitators. Data were analysed using framework analysis. Results: Programme recipients' and facilitators generally reported positive experiences of Positive Family Connections and described beneficial effects on wellbeing and family relationships. We developed a model showing how the lived experience of facilitators and positive approach led to reductions in isolation and perceived changes in mindset that were described as improving family carers' wellbeing and family relationships. Conclusions: Positive Family Connections appears to be an acceptable programme which programme recipients and facilitators perceive to be beneficial.