Purpose: The purpose of this study is to analyze the correlation between obesity stress, self-esteem, and adaptation to school life according to body mass index of elementary school students in higher grades and to provide basic data for the development of health education programs. Methods: A convenience sampling method was used to select four elementary schools. Self-reporting questionnaires were distributed to the subjects to collect data, which were then analyzed using the SPSS 18.0 program. Results: The higher the obesity index, the more obesity stress the students experienced. Second, the lower the level of obesity, the higher both self-esteem and the level of adjustment to school life were. There was a meaningful correlation between obesity stress, self-esteem, and adjustment to school life. Conclusion: The study results are expected to be useful in serving as a basic material for the development of programs that can improve students' adjustment to school life and self-esteem while reducing their stress caused by obesity.