This study aimed to explore mothers’ experience of implementing Lego Therapy at home within the family. Following a Lego Therapy training session, mothers carried out hourly sessions with their child with an autism spectrum condition and the child’s sibling, once a week, for 6 weeks. Mothers were interviewed following the intervention, and the data were analysed using interpretative phenomenological analysis. Themes emerged around improved family relationships, a positive impact on the child as an individual, and changed maternal, sibling and child perspectives. Challenging and facilitative aspects also emerged, as did some ambivalence about the impact of the intervention in the wider context. The findings are supportive of previous Lego Therapy studies and have implications for strengths-based service provision.