Children who are unhealthy are at higher risk for school problems than students who are free from medical problems. Students with poor health have a higher probability of school failure, grade retention, and dropout. The relationship between student health and academic success is complex. Common manageable factors of student health are nutrition, maintaining healthy weight, and physical fitness. Through a comprehensive literature review the relationships among school achievement and nutrition, maintaining healthy weight, and physical fitness are examined. Furthermore, the efficacy of educational programs to improve nutrition, maintain healthy weight, and increase physical fitness is evaluated. The complexity of the relationship among variables is presented and areas for future research and practice for school psychologists are described.