Aim: This study was conducted to determine the effect of middle and high school students' emotional eating behavior on obesity. Method: A descriptive, correlational, and cross-sectional study design was used. The sample consisted of 267 students studying in 5th, 6th, 7th, 8th, 9th, 10th, 11th, and 12th grades. Data were collected using a Child Information Form and the Emotional Eating Scale. The researchers measured the students' height and weight and calculated their body mass indices (BMI), and BMI percentiles were evaluated according to age and gender. Percentage calculations, mean scores, Spearman correlation analysis, Pearson's correlation analysis, and multiple regression analysis were used in the analysis of the data. Results: Of the students participating in the study, 54.7% were girl and 45.3% were boy. It was determined that 28.4% of the students were overweight and obese. As a result of multiple regression analysis, it was determined that students' emotional eating behavior explained 25% of obesity (p < 0.001). It was found that anxiety-anger- frustration, one of the subscales of the emotional eating scale, was the only variable that significantly predicted students' obesity status (β = 0.387). Emotional eating significantly predicted the obesity status of boy and girl students (p < 0.001). Conclusion: In this study, it was concluded that students' emotional eating behavior affected obesity. Implications for practice: In line with these results, it is recommended that studies on other variables that may predict the effect of students' emotional eating behavior on obesity should be conducted and that nurses should contact schools to conduct emotional eating behavior screenings and provide emotional eating education for students who exhibit emotional eating behavior.