The study investigated how children's willingness to internalize mothers' values affected the associations between mothers' performance goals for their children and the development of children's perfectionism and depression. The participants were 59 Hong Kong fifth graders and their mothers. The results showed that internalization, as a child factor, moderated the association between mothers' performance goals for their children and children's self-oriented perfectionism, but not socially prescribed perfectionism. Children's internalization also moderated the association between mothers' performance goals for their children and children's depression. Among the children who were more willing to internalize their mothers' values, their mothers' performance goals for them were correlated positively with their self-oriented perfectionism, but negatively with their depression. Paradoxically, internalization appeared to be a risk and also a protective factor in the psychological well-being of children.