This paper summarizes the historical and legislative backgrounds leading to statewide testing of health-related physical fitness in Texas children grades 3-12 as mandated by Texas Senate Bill 530. The rationale and goals for an associated research project (the Texas Youth Fitness Study, funded by the Robert Wood Johnson Foundation) to evaluate data collected from the statewide initiative are provided. The study investigated the relations between health-related physical fitness and educational variables, including academic achievement, absenteeism, and negative school incidents. It also provides unique insights into the quality (both reliability and validity) of collected data and implications of large-scale school-based physical fitness testing. Teacher commentary and experiences add to the description of the data collection processes. Last, the relations between psychosocial variables and health-related fitness in middle school students are described.