PURPOSE: To systematically review studies about the quality of life (QOL) of children with various mental disorders relative to healthy controls and to describe limitations in these studies. METHODS: Relevant articles were searched using different databases, by checking reference lists and contacting experts. We included articles that either compared children with mental disorders to healthy controls/norm values or made such a comparison possible. RESULTS: Sixteen out of 4,560 articles met the pre-defined inclusion criteria. These studies revealed that the QOL of children with various mental disorders is compromised across multiple domains. The largest effect sizes were found for psychosocial and family-related domains and for the total QOL score, whereas physical domains generally were less affected. The most important limitations in the existing literature include the lack of study samples drawn from the general population, the failure to use self-ratings, not considering item overlap between measuring QOL and assessing for the presence of a particular mental disorder, and not determining whether the children were receiving medication for their mental disorder. CONCLUSIONS: Children with mental disorders experience a considerable reduction in QOL across various domains. Research studies that avoid previous limitations are crucial to fill existing knowledge gaps.