The aim of this study was to investigate the relationship between difficulty in regulating emotions and body image dissatisfaction, rumination, and eating behaviors in second-year high school students in Ardabil city. The present study was descriptive-correlational and designed within the framework of applied studies. The statistical population included all male and female second-year high school students in Ardabil city in the academic year 1404-1405, and 200 people were selected as samples using stratified random sampling. Data collection tools included the Gratz and Romer Difficulty in Regulating Emotions Questionnaire (2004), the Littleton Body Image Dissatisfaction Questionnaire (2005), the Trapnell-Campbell Rumination Questionnaire (1999), and the Dutch Eating Behaviors Questionnaire (1986), the reliability and validity of which had been previously confirmed in domestic and international studies. The data were analyzed using descriptive and inferential statistics, including Pearson correlation and multivariate regression. The results showed that there was a positive and significant relationship between difficulty in emotion regulation and a combination of body image dissatisfaction, rumination, and eating behaviors (r = 0.572, p < 0.001), and these variables were able to predict a significant portion of the variance in difficulty in emotion regulation. Regression analysis showed that rumination had the greatest impact (β = 0.564), followed by eating behaviors and body image dissatisfaction. These findings indicate that negative attitudes toward the body and negative cognitive processes such as rumination can contribute to difficulty in emotion regulation in students. Based on the results, it is recommended that emotion regulation skills training programs and cognitive-behavioral interventions be implemented in schools to reduce rumination and improve students' emotion management.