Study objective - To clarify concepts and methodological problems in existing multidimensional health status measures for children. Design - Thematic review of instruments found by computerised and manual searches, 1979-95. Subjects - Nine health status instruments. Main results - Many instruments did not satisfy criteria of being child centred or family focussed; few had sufficient psychometric properties for research or clinical use; underlying conceptual assumptions were rarely explicit. Conclusions - Quality of life measures should be viewed cautiously. Interdisciplinary discussion is required, as well as discussion with children and parents, to establish constructs that are truly useful.