This study aimed to determine the relationship of sleep quality with the percentage of body fat in children (ages 9-12 years) in the Elementary School Complex of IKIP I Makassar. The study used the Analytical Survey design with a cross-sectional approach. The researcher will compare the causes and consequences variables simultaneously and explain the relationship between the research variables through hypothesis testing. This study uses quantitative methods, namely through assessing sleep quality and body fat percentage using a questionnaire. The data was collected through in-depth interviews and observations of children. Sampling uses purposive sampling and data analysis using the Chi-Square test. The results of the study showed that there was no significant relationship between sleep quality and body fat percentage. However, after being tested based on the components of sleep quality, it was seen that good sleep quality and poor sleep quality in component 3 (sleep duration). Moreover, component 4 (daily sleep efficiency) had a significant relationship between sleep duration and daily sleep efficiency with body fat percentage. Recommendations from this research are needed on the relationship between sleep quality and student achievement index.