Although children with Williams syndrome (WS) are strongly socially motivated, many have friendship difficulties. The parents of 21 children with WS and 20 of the children themselves participated in a semi-structured interview about the children's friendships. Parents reported that their child had difficulties sustaining friendships and low levels of interaction with peers. Barriers to friendships included difficulties with play and self-regulating behaviour. However, there was within-group variability, with a small number of children reported to have strong friendships. While parents reported friendship challenges, all of the children named at least one friend, and most said that they had never felt excluded by their peers. Future research is needed to determine optimal ways to support children with WS in their friendships.