Background: Young people with Down syndrome and their families often contend with social stigma. The present study examined this issue from their mothers' perspective. Methods: An interpretative phenomenological approach (IPA) was used to explore mothers' perceptions of their child's developing awareness of their disability and associated social stigma. Interviews were carried out with nine mothers of young people with Down syndrome aged 9-16 years old. Results: All mothers were sensitive to the stigmatized status of Down syndrome and were at pains to protect their child from becoming aware of it. Some mothers had talked about Down syndrome with their child. Other mothers carefully monitored their child for signs that they were ready to talk about it. On the surface, all mothers believed that their child had a limited insight into Down syndrome and stigma but detailed discussion revealed more complex insights. Conclusion: Mothers expressed uncertainty and anxiety about when and how to talk to their child about Down syndrome.