Introduction: Today, obesity caused by emotional overeating has become a ubiquitous phenomenon with major side effects. Aim: The present study aimed to compare the effectiveness of acceptance and commitment-based group therapy and group schema therapy in emotion regulation difficulties and body mass index (BMI) of obese people with emotional eating. Method: In this quasi-experimental study with a pretest-posttest, control group, follow-up design, the population included all men and women, aged 21-50 years, who were referred to the nutrition and obesity clinics of Tehran, Iran, from September 2020 to December 2020. The study sample included 45 obese people with emotional eating, who were selected through convenience sampling among individuals visiting Mehrdadi and Behpouyan nutrition and obesity clinics and randomly assigned to two experimental groups and one control group. The data collection tools were the Dutch Eating Behavior Questionnaire (1986), Difficulties in Emotion Regulation Scale by Gratz and Romer (2004), and BMI measurement. The collected data were analyzed using analysis of covariance and Bonferroni's post-hoc test in SPSS version 24. Results: Results from Covariance analysis showed that there was a significant difference between the scores of control and experimental groups. Compared to the control group, the experimental groups have improved emotion regulation and reduced body mass index. In addition to results indicated that acceptance and commitment-based group therapy and group schema therapy similarly improved emotion regulation and reduced the BMI of obese people with emotional overeating (P<0.05). Conclusion: Acceptance and commitment-based group therapy and group schema therapy were effective methods in improving emotion regulation difficulties and reducing the BMI of obese people with emotional eating. So it's suggested to use these methods in the treatment of obese people suffering from emotional overeating.