Background/aim: Although the connections between health and school performance are well accepted, data on the specific mechanisms that account for this relationship is remarkably scant. The aim of this study was to characterize the longitudinal associations between child health and academic achievement among 4th-8th graders followed for 3 years in 3 school districts in the USA. Design/Methods: Project Healthy Pathways, an NIH-funded study, enrolled 2,091 4th-6th grade students (90% with complete data) and used a cohort sequential design to monitor changes over 3 years in their health, as reported by children (ACASI) and parents (mailed questionnaires), and their performance on standardized achievement tests and annual grade point averages. Results: Both the quantity and pattern of children's health significantly predicted achievementtest scores and grade point average. Although health declined for many children during entry into adolescence, about 20% experienced large decrements in health. These children were more likely girls, had low self worth, and experienced early puberty. Significant positive predictors of school performance were good nutrition habits, good coping, adequate levels of sleep, and feeling connected with adults, and negative predictors included feelings of stress, physical discomfort, being a bully victim, having a special healthcare need, and being overweight. Conclusions: In this longitudinal study, characteristic patterns of child health predicted future academic achievement. These findings suggest that health promotion efforts provided to children in elementary school may have beneficial effects on academic performance in adolescence.