Emotional self-regulation plays a very critical role in promoting intelligence beliefs and improving students' academic performance. Through emotional self-regulation, students can believe in the effectiveness of their intelligence and achieve higher performance in their educational and learning processes. The aim of the present study was to investigate the relationship between IQ beliefs and chemistry performance with emotional self-regulation mediation in students. This study was applied in terms of purpose, and considering data collection procedure, it was descriptive-correlational. The statistical population included all 275 female students of 11 public senior high schools in Mahmudabad, the 11th grade, in the academic year 2020-2021. Based on the census method, the whole population of the research community was used as a sample. The instruments used for data collection included the Intelligence Beliefs Questionnaire (Babaei, 1998) and the Emotion Self-Regulatory Questionnaire (Gross & John, 2003). Also, the final score of the chemistry course was used as the chemistry performance of the participants. To analyze the data, Kaiser-Meyer-Olkin test, Bartlett’s test, correlation coefficient, regression, path analysis and structural equation modeling were used. The findings showed that there was a statistical significant relationship between intelligence beliefs, emotion self-regulation and students' chemistry performance. In addition, intelligence beliefs and emotion self-regulation have a direct effect on students' performance in chemistry. Also, intelligence beliefs have a significant effect on the performance of students' chemistry lessons through the mediation of emotion self-regulation. It should be mentioned that the research model had a very good fit. Given that intelligence beliefs and emotion self-regulation can predict the performance of students in the chemistry course, it is recommended to modify cognitive beliefs and teach emotion self-regulation techniques in order to improve students' academic performance.