Background: Health is recognized as an important factor in children's educational achievement, and school-based health education programs are recognized for their potential long-term impact. However, the extent to which children conceptualize health similarly as adults, and the nature of their understandings of health, remain cloudy. Purpose: Therefore, the purpose of this study was to describe children's conceptions of health, and examine their conceptions in light of age and sources of health-related information. Design and methods: Participants were 108 children ages 6-10 (58 male, 51 female) attending a university-based summer activities day camp. The first day, children met in small groups, where they were asked to draw a picture of a healthy and an unhealthy person. The next day, children met individually with one of the researchers for a taped semi-structured interview. Participants were asked to describe their drawings, what it means for a person to be healthy, how one can tell if a person is healthy or unhealthy, and what a person can do to be healthy. They also were asked about their sources of health information. Results: Our results indicated that children's conceptions of health ranged from a vague understanding of being happy vs. sad, and conceiving health as lack of illness, to conceptions focused on behavior. Children's understandings of health showed developmental differences with respect to the ability to grasp abstract qualities. However, of potentially greater importance was the tendency for children to move from non-behavioral conceptions (viewing health as related to sickness or appearance) to the conception of health focusing on behavior. When asked about sources of health information, children predictably indicated learning about health from parents and school. This finding highlights the importance of including health education in the elementary years, and of encouraging parents to be involved in supporting such. Conclusions: Knowledge is an important component of physical education and health education programs, with the purpose of developing an understanding of the relation between one's behaviors and health outcomes, and the activities needed for desired outcomes. Consistent with this, American Association for Health Education (AAHE) standards currently identify levels of each standard for grades K-4, 5-8, and 9-11. Further research to identify differences in the applicability of psychological theory can improve program design and delivery. (Contains 3 tables and 5 figures.)