The present paper describes a study in which 13 children aged 9-11 years, of diverse ethnic, linguistic, and socio-economic backgrounds, were asked to use a digital camera and small notebook to document the range of things they consider to be healthy and unhealthy. Using open-ended interview questions, the children were then asked to explain each item, including what it was, why they chose it, and why they thought it was either healthy or unhealthy. The range of definitions of "healthy" and "unhealthy" invoked by the children was surprisingly broad, encompassing not only illness and proper nutrition, but also environmental health, mental health, cleanliness, and other meanings. Findings across all 13 children are displayed, and a case study of one child serves as a detailed example of the types of meanings children ascribe to the words "healthy" and "unhealthy", as well as the kinds of analyses being employed on these data. The theoretical implications of these results for research on children's ideas about health, as well as implications for the design of health interventions, are discussed. (Contains 5 figures, 2 tables, and 3 notes.)