Abstract: Joshi, P, Bryan, C, and Howat, H. Relationship of body mass index and fitness levels among schoolchildren. J Strength Cond Res 26(4): 1006–1014, 2012—Childhood obesity is an epidemic in the U.S.A., and understanding aspects of fitness is critical in implementing effective interventions. The purpose of this study was to analyze the relationship of obesity levels with the fitness levels of public school children in Louisiana. Over 7,000 school children participated in body mass index (BMI) and Fitnessgram® subtests including the Progressive Aerobic Cardiovascular Endurance Run (aerobic capacity), curl-ups, trunk lifts, push-ups (strength and endurance), and shoulder stretches (flexibility). The fitness measures and BMI were analyzed using chi-square and logistic regression to test for any significant relationships. The results indicated that the participants with healthy BMIs have the highest levels of physical fitness. The differences between the fitness levels of obese and healthy children were statistically significant. This study demonstrated a direct relationship between BMI status and fitness levels as measured by the Fitnessgram® among study participants. This finding is not exceedingly surprising, as common sense tells us that the heavier a person is, the less likely he or she is to be physically fit. However, this study is an important first step in understanding weight issues in children. This information can be used to develop data-driven interventions to assist children in becoming healthier and more physically fit.