The value of parental engagement in the learning of children and young people has repeatedly been shown to be of value in the literature, and in practice. One of the ways many parents feel they can be involved in their children's learning is through support with homework, and homework forms a ubiquitous part of schooling in most systems. However, parental engagement with homework has been shown to be problematic in the literature. This paper combines the literature on parental engagement, with that on both the effectiveness and purposes of homework and that on the importance of mastery orientations for young people, to argue that the effective forms of parental engagement in young people's homework will be engagement that supports and leads to mastery orientations on the part of children. The paper includes a schematic for this engagement and concludes with principles for designing homework tasks.